Javascript string contains substring If the substring isn’t contained in the string, the method will return -1. Jun 14, 2016 · I have a string containing a person's first and last name such as John Doe. '; console. Feb 19, 2023 · Learn 4 approaches to check if a string contains a substring in JavaScript, using regular expression, includes(), indexOf() and a for loop. Several methods are used to check if a string contains another substring in Javascript. Feb 12, 2016 · To check the substring within the string you can use includes jQuery function like this var sub_str = "find" var main_str = "find me if you can" result = main_str. Let's discuss one of the most common tasks bellow. JavaScript Program to Check Whether a String Contains a Substring. If the string does not contain the substring, indexOf() returns -1. includes(); ES6 contains inbuilt method (includes) in String's prototype, which can be used to check if string contains another string or not. To use the ‘includes()’ method in JavaScript, you can simply call it on a string object with the substring as an argument. Just do the following myArray. includes(), introduced in ES6. 在编写 JavaScript 程序时，你可能需要检查一个字符串是否包含一个子字符串。子字符串是另一个字符串中的字符串。 具体来说，你可能需要检查一个单词是否包含特定字符或特定字符集。 Aug 24, 2024 · Here substring searches help analyze whether strings contain relevant keywords, conventions or formats. However, there are two other ways to search if a string contains a specified character or a phrase. contains(text, Dec 21, 2016 · I looks like your if logic here was if the first name doesn't contain "stream" or name 1 and 2 do not contain stream but your checking name 1 with lowercase "stream" and name 2 with uppercase "stream". in ITSM forum 2 weeks ago Applying complex Query in ITSM forum 2 weeks ago Using Image Variable Type to Put In Image Into Knowledge Base Article in ITSM forum 2 weeks ago May 25, 2023 · In this article, we'll explore different approaches to check whether a string contains a substring in JavaScript. Learn the canonical way, and also find out all the options you have, using plain JavaScript. includes which accepts a substring as an argument and will return a Nov 8, 2018 · Ask questions, find answers and collaborate at work with Stack Overflow for Teams. var a = 'good morning'; Here are the different ways to check if string contains substring in JavaScript. include() that we have covered so far, String. See examples, explanations, and code snippets from the Stack Overflow community. Mar 3, 2025 · In JavaScript, checking whether a string contains a specific substring is a common task. Apr 10, 2025 · Strings are useful for holding data that can be represented in text form. So if the search is larger or equal to 0, the substring exist. The includes method is a powerful tool for this purpose, allowing People here are making this waaay too difficult. The substring() method extracts characters from start to end (exclusive). It returns the index of the first occurrence of the specified substring within the string, or -1 if the substring is not found. Dec 3, 2024 · Here are the different ways to check if an array of strings contains a substring in JavaScript 1. May 20, 2022 · String. May 2, 2023 · Another way is to use the string indexOf() method, which returns the index of the first occurrence of the substring. I would like to convert this string to John D. The method searches the string for the substring in question and returns the index of the first occurrence if there is one. Mar 14, 2019 · So, you can easily check if a string contains a particular substring using the . includes("#") May 16, 2024 · The indexOf method in JavaScript is a simple and efficient way to check if a string contains a substring. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. Here's an example: Feb 15, 2011 · What is the regex for simply checking if a string contains a certain word (e. Oct 27, 2022 · 原文： How to Check if a String Contains a Substring in JavaScript. includes("hello", "hi", "howdy"); Imagine the comma states "or". Jul 27, 2022 · JavaScript ; String ; String contains substring ; Check if a string contains a substring in JavaScript String. If the expression and the string match it results in true and returns token ( which is the string the switch statement is operating on ). Using includes() and filter() method. Check String contains substring 1. displayed-result'). You can try to run the following code to check whether the string “Tutorialspoint: Free Video Tutorial” contains a substring “point” in or not. The 'every' method executes the provided callback function once for each element present in the array until it finds one where callback returns a falsy value (a value that becomes false when converted to a Boolean). replace() is regexp-based; if you pass in a string as the first argument, the regexp made from it will not include the ‘g’ (global) flag. Also, since you only want to match a sub-string, you'll need to remove the start and end anchors ^ and $. Sep 9, 2019 · To check if a string contains a substring in JavaScript: Call the String. Aug 25, 2023 · One of the simplest and most straightforward ways to check if a string contains a substring in JavaScript is by using the includes() method. The actual implementation comes from RegExp. The following shows you different ways of finding a substring in a JavaScript string: Using String. log(string. count = 12 Jan 8, 2018 · Need to loop an array of strings and check against with another string, which is passed in the string. includes() Method. includes() in JavaScript: Call the String. Use a regular expression to check if a string contains only alpha or alphanumeric characters in JavaScript. Apr 29, 2020 · I need to test whether the innerText of a element contains a substring using testcafe, but I'm not able to figure out the right way to do that. Jan 24, 2023 · Checking if String Contains a Substring in JavaScript To check if a string contains a substring in JavaScript, use the string. Unlike String. It is a simple and common task, but different languages handle it in different ways. This method returns a boolean value indicating whether the target string contains the specified substring. The first parameter is the substring to search for, and the second optional parameter is the Feb 13, 2024 · Hi @gunishi ,. It's a simple method that returns a boolean value depending on whether the string contains the substring or not. This method returns true if the substring is found in the string, and false otherwise. includes('To be')); One of the most basic tasks in any programming language is determining whether a string contains a given substring. Answer: Use the indexOf() Method. The String. Here's an example of how to use the includes() method:. : var str = "foobar"; var containsFoo = str. search(searchValue) searchValue is a regular expression or a string (will be converted to a regular expression). includes (substring, starting_point) array_name. search(), String. For example, if I apply a search for "on" for the string, "phones are good", it should return false. If start is greater than end, arguments are swapped: (4, 1) = (1, 4). The default position is 0. includes() str. 'Test')? dedicated "substring" methods tend to be faster in this case, because it Feb 2, 2024 · Use String. Follow our guide for simple and effective solutions. indexOf("the"); // position = 5 If the given string isn't present, indexOf will return -1. It returns true if the substring is found within the string, and false otherwise. If I change the observation string to a very long UTF-8 multibyte text, the results change drastically? Also, the results changed with change in position of substring in the observation string. Selector('. The substring() method does not change the original string. As you can see, a boolean value is returned since the string "stack" is a substring of stackabuse. var filterstrings = ['firststring','secondstring','thridstring']; var passedinstring = localSt Jul 27, 2011 · To replace substring. 3586. Let's have a look at how to check if a string contains a substring in JavaScript. Mar 21, 2022 · The best way one can check if a string contains a substring is to utilize the includes() method. Javascript match method accepts a regular expression as a parameter and if the string contains the given substring it will return an object with details of index, substring, input, and groups. If the returned value is not equal to -1, the string contains the substring. Normally, I would just use substring(0,1) on the last name variable, but how can I achieve this when the first and last name are one string with a space in between? Sep 16, 2010 · @EscapeNetscape: Nice to see a benchmark link. match() seems to check whether part of a string mat Jun 18, 2016 · Just wondering, is there a way to add multiple conditions to a . May 10, 2020 · JavaScript str. includes(), String. Unfortunately, JavaScript's built-in tools for doing so leave quite a bit to be desired. Javascript string substring check May 25, 2024 · Check if a string contains a substring in JavaScript. Jan 21, 2025 · The ‘includes()’ method is a simple and straightforward way to check if a string contains a specific substring. includes(substr); true. Dec 21, 2023 · Cómo usar el método includes() de JavaScript. findIndex() method to iterate over the array. var string = "foo"; var substring = "oo"; console. Using regex for a task like this gives you a lot more flexibility than with the previous methods where you can only check for a constant string. Learn how to use the includes() method to check if a string contains a specified string. Here's an example that demonstrates the usage of the includes() method: Aug 18, 2015 · You can then check for the presence of a string by using indexOf like so: var position = "Find the string". Jan 10, 2025 · The String constructor property in JavaScript is used to return the string constructor function for the object. substring case iterates over a potentially much smaller string. How to check if one string contains substring. prototype[Symbol. To do a case insensitive check if an array contains a string: Use the Array. Jan 2, 2025 · H ere are the different ways to check if an array of strings contains a substring in JavaScript. Example 2: With variable substring. [GFGTABS] JavaScript const a = Apr 24, 2019 · There are multiple ways to check if a string contains a substring in JavaScript. You can also include the position at which to begin searching the string for the substring. match](). Checking whether a string contains another string or not is very common in JavaScript and as well as in other programming languages. Using includes() method. See examples, code snippets and FAQs on this topic. substring also risks Voici une liste des possibilités actuelles: 1. JavaScript May 8, 2023 · Photo by Markus Spiske on Unsplash. Example. Jan 19, 2023 · Si vous utilisez un navigateur moderne ou une version avancée de node, on peut utiliser la méthode ES6 includes(). May 16, 2019 · There's two common ways to check whether a string contains a substring in JavaScript. indexOf(), String. The includes() method is arguably the most common way of checking if a string contains a substring. Whether you are a beginner or an experienced developer, this article will provide you valuable understanding into testing strings for substrings. Try Teams for free Explore Teams Apr 14, 2022 · 在本指南中，我们将学习如何使用includes() 方法来查找字符串中的子串；但首先，让我们讨论JavaScript中includes() 的语法。 语法。 string_name. indexOf() This is a three-step process: Call the indexOf method on the string, passing it the substring as a parameter. Nov 7, 2024 · JavaScript offers several methods to check whether a string contains a specific substring. Whether you need case-sensitive checks or prefer a flexible, case-insensitive approach, this guide has it covered. includes(sub_str) if result{ * Stuff todo if result found }else{ * Stuff todo if result not found } result true; // if you have sub string finder method separately and calling it from The substring() method extracts characters, between two indices (positions), from a string, and returns the substring. includes() to Check if a String Contains Substring in JavaScript Use String. (More on regex anchors) Your code becomes: Mar 13, 2025 · The implementation of String. The includes() method is the most simple and modern way to check if a string contains a specific substring. JavaScript offers different ways to perform this operation. It returns a Boolean value indicating whether the substring is found within the string. I tried array. JavaScript String substring() substring() is similar to slice(). May 1, 2018 · JavaScript offers many ways to check if a string contains a substring. includes() Mar 26, 2025 · There are subtle differences between the substring() and substr() methods, so you should be careful not to get them confused. 1. findIndex(element => element. indexOf('foo') >= 0; // true The indexOf method returns the character index where the first occurrence of the specified value is encountered, if not found, it returns -1 . According to npm trends, the popular string-includes substring search package receives over 2 million downloads per week in frameworks like React, Vue and Angular. substr()'s start index will wrap to the end of the string if it is negative, while substring() will clamp it to 0. Example-2: Using a substring and a starting position We can also check whether the target substring is located at a specific index. The simplest and fastest way to check whether a string contains a substring or not in JavaScript is the indexOf() method. I am kind of stuck on how to set it so that if I get three "True", I want to execute something, other I want it to do something else. Introduction to JavaScript String includes() method The includes() method performs a case-sensitive search and determines if a substring is included in a string: Oct 24, 2010 · /** Function that count occurrences of a substring in a string; * @param {String} string The string * @param {String} subString The sub string to search for * @param {Boolean} [allowOverlapping] Optional. includes(term, start) method, which checks if the string contains the substring. You can use either String. Jun 9, 2016 · I have multiple sub-strings that I want to find in a single string and if all three are found then do this, if not, do something else. May 24, 2010 · The test in this case is token. Depending on your needs, choose includes() for a straightforward, case-sensitive check, indexOf() to possibly retrieve the substring's position, or regular expressions for more complex matching requirements. org Nov 16, 2024 · Learn how to use includes(), indexOf() and regular expressions to check if one string is substring of another in JavaScript. Nov 24, 2009 · Learn how to check whether a string contains a substring in JavaScript using various methods, such as includes, indexOf, or KMP algorithm. Topic: JavaScript / jQuery Prev|Next. If you expect majority successes or only small inputs, . See examples, syntax, parameters, return value and browser support for this ECMAScript6 feature. How to check whether a string contains a substring in JavaScript? By using the following methods, you can easily check whether a string contains a substring in JavaScript: Sep 15, 2023 · In this article, we will discuss the JavaScript Test if String Contains Substring. Apr 11, 2025 · This method takes two parameters – the substring that you want to search for, and an optional parameter that specifies the starting point of the search. And, it should return true for "keep it on the table". Aug 18, 2021 · To check if a string contains a substring in JavaScript the easiest way is to use String. How to Check Whether a String Contains a Substring in JavaScript. var position = "Find the string". See examples, syntax and pros and cons of each method. indexOf(substring) !== -1); // true Aug 26, 2019 · If we look at the docs for String. The indexOf() method is case-sensitive and accepts two parameters. search() accepts a regular expression as its parameter. indexOf("notFound"); // position = -1 You can then use this in an if statement like so Sep 6, 2023 · If all you need to do is get a boolean value indicating if the substring is in another string, then this is what you'll want to use. Summary: in this tutorial, you will learn how to use the JavaScript String includes() method to check if a string contains a substring. Jan 9, 2023 · I want to use JavaScript (I can also use jQuery) to do check whether a string matches the regex ^([a-z0-9]{5,})$, and get a true or false result. . Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. JavaScript · March 24, 2024 Check if a JavaScript string contains only alpha or alphanumeric characters. includes()provides the most simple and popular way to check if a string contains a Apr 7, 2011 · Pretty straight forward. indexOf() method. [GFGTABS] JavaScript const a = Sep 22, 2022 · When you’re testing if a string contains a specific substring, you might be inclined to use a method like indexOf(). var str = 'To be, or not to be, that is the question. indexOf() method, str. We will see the built-in May 22, 2015 · You don't really need jQuery for such a simple thing, you can simply use the indexOf method of String objects, e. To understand this example, you should have the knowledge of the following JavaScript programming topics: JavaScript String; Javascript String includes() JavaScript String indexOf() Oct 2, 2012 · In the first alert(), JavaScript returned "-1" - in other words, indexOf() did not find a match: this is simply because "JavaScript" is in lowercase in the first string, and properly capitalized in the second. includes("substring")) findIndex() is an ES6 higher order method that iterates through the elements of an array and returns the index of the first element that matches some criteria (provided as a function). match doesn't do much other than calling the Symbol. However, for more flexible testing and conditions, using regular expressions Jan 7, 2021 · In this tutorial, we discussed the basics of strings in JavaScript. search() is another method that you can use to check if a string contains another word, substring or character inside the main string. # Ignoring case Check if Array contains String - Array. match(/spo/) which states the match the string held in token against the regex expression /spo/ ( which is the literal string spo in this case ). ES5 et plus indexOf Feb 20, 2024 · Here are the different ways to check if an array of strings contains a substring in JavaScript 1. Other search methods you can consider include: May 30, 2024 · JavaScript is an incredibly versatile language, and working with strings is one of its many strengths. As you can see, the basic syntax allows you to easily check if a string contains a substring in JavaScript. replace('-',''); Output: -----check Jquery removes first '-' from my text. Jun 8, 2017 · I have an array like this: array = ["123", "456", "#123"] I want to find the element which contains the substring "#". We will create an array of strings, then use includes() and filter() methods to check whether the array elements contain a sub-string. search(substring) to check if a string contains your substring. it looks like you just want both names not to contain stream, this can be much more easily performed like this. Compare the returned value to -1 . includes() we can see it takes a string, not a regular expression. ¿Qué es el método includes() de JavaScript? Veamos su sintaxis. substring is likely faster. But not working for me var str='------check'; str. I'm interested in finding if a string contains a word. Using the includes() method. This operation is useful for various applications, such as searching for keywords in user input, filtering data, or validating form inputs. [GFGTABS] JavaScript const a = Mar 1, 2024 · We just need the strings to be in the same case to be able to determine if the substring is contained in the string. Checking if a string contains a substring is one of the most common tasks in any programming language. Mar 31, 2025 · Check Whether String Contains Substring. To check if a string contains substring JavaScript, we commonly refer to the includes() method because of its targeted design towards a string and the letters search. Using includes() Method. May 25, 2016 · For reducing the function you can use every() and indexOf() methods. Works perfectly fine when search term is a variable. If the separator is omitted, the returned array will contain the whole string in index [0]. Sep 8, 2019 · To check if a string contains a substring using String. Using includes() You can use includes() function to check if a string contains a substring or not. includes() The most straightforward substring search option is String. (ES6) includes - aller à la réponse var string = "foo", substring = "oo"; string. indexOf() to Check if a String Contains Substring in JavaScript This tutorial teaches how to check if a string contains a substring in JavaScript. lastIndexOf on a long string that's going to return false is going to iterate over the entire string (O(N)), whereas the . innerText = '12 results' Selector('user-details'). To check if a string contains substring or not, use the Javascript match method. This method returns the index or position of the first occurrence of substring within Syntax string. Cómo usar el método indexOf() de JavaScript. String. match(), regular expressions, or 3rd-party library like Lodash. El método includes() de JavaScript se introdujo con ES6 y la forma más común y moderna de verificar si una cadena contiene un caracter específico o una serie de caracteres. It is often used in arrays, and the same can be applied with strings. includes (element, starting_point) 在JavaScript中include()方法需要两个参数。 substring/element。第一个 Methods To Check for JavaScript String Contains. May 4, 2016 · Is there a way in lodash to check if a strings contains one of the values from an array? For example: var text = 'this is some sample text'; var values = ['sample', 'anything']; _. How to check whether a string contains a substring in JavaScript? 3627. includes(substring); 2. La méthode includes() renvoie true si la sous-chaîne se trouve dans la chaîne de caractères qu’on teste. The function which is returned by this property is just the reference to this function, not a string containing the function's name. Oct 18, 2022 · Another way to check if a string contains a substring in JavaScript is to use the string. The indexOf method would return -1 if the substring is not present in the string. Let us say you have the following string. After that, we discussed three ways in which you can check if a string contains a substring in JavaScript: using includes(), indexOf(), and regex. I need to remove One of the most basic tasks in any programming language is determining whether a string contains a given substring. Oct 21, 2022 · The code above returns 8. Dec 8, 2021 · Hi, in this tutorial, we are going to talk about 7 Ways to check if a string contains a substring or not in javascript. includes() method. search() method. includes() method on the string. there's not much that can be done about that without doing much more detailed inspection of the strings. includes method, for example: var value = str. Using includes() and filter() methodWe will create an array of strings, then use includes() and filter() methods to check whether the array elements contain a sub-string. Here's how you can do it: Using indexOf(): You can use the indexOf() method to check if a string contains a specific substring. findIndex. Sep 6, 2023 · One of the more useful and powerful ways to check for a substring is to use regular expressions, or regex. In javascript, I need to check if a string contains any substrings held in an array. First of all, let's take a look at using String. log(str. It takes a substring as an argument and returns a boolean value, which is exactly what we need. Mar 13, 2025 · The includes() method of String values performs a case-sensitive search to determine whether a given string may be found within this string, returning true or false as appropriate. indexOf() and String. If there is a substring it returns the index it was found (some number from 0 to n), otherwise if it's not found it returns -1. The includes() method is a simple and straightforward way to check if a string contains a substring. includes(substr) . The first parameter is the string to search for, and the second optional parameter specifies the position from which to search. Remove duplicates from the string variable type. Checking whether a string contains a specific substring is a common task in JavaScript. This option is essential if you want to replace all occurances of the search string (which is usually what you want). Dec 2, 2024 · Here are the different ways to check if an array of strings contains a substring in JavaScript 1. If the string contains the substring, indexOf() returns the index of the first occurrence of the substring. . let searchTerm = "world"; let str = "Hello world!"; str. Dec 2, 2024 · Here are the different methods to check whether a string contains a substring in JavaScript. g. match method of the argument with the string as the first parameter. Dec 6, 2022 · It is true that the string JavaScript string contains is easy contains the string substring. Whether you're building a web application, processing data, or just playing around with code, you may need to check if a string contains a specific substring. If the string does not contain the substring then it will return null. Instead, try RegExp. Jun 10, 2022 · Through this tutorial, you will learn how to check whether a string contains a character or substrings in javascript using the javaScript include(), indexOf() method. For example you can use string. Jun 24, 2024 · Learn the best methods to check if a string contains a substring in JavaScript. It works like this: > let str = 'stackabuse'; > let substr = 'stack'; > str. In script, you can check if a string contains a specific substring using the indexOf() method or a regular expression. The two parameters of substr() are start and length, while for substring(), they are start and end. Pass the substring as a parameter, e. prototype. The more modern way is the String#includes() function. Conditionally check if the returned value is not equal to -1. This built-in function on the String object checks if a string contains a substring. Some of the most-used operations on strings are to check their length, to build and concatenate them using the + and += string operators, checking for the existence or location of substrings with the indexOf() method, or extracting substrings with the substring() method. Checks if str contains "world", which it does so returns true. The JavaScript number constructor, string constructor, Aug 14, 2016 · When working with JavaScript, determining whether a string contains a specific substring is a common task. Jan 26, 2010 · Javascript seems to use locale "C" for string comparisons so the resulting ordering will be ugly if the strings contain other than ASCII letters. prototype's indexOf method. Understanding JavaScript String Basics Aug 16, 2014 · Note that there are plenty of methods that allow you to do this. Mar 1, 2024 · # Check if a String contains a Substring with String. lastIndexOf is likely faster - otherwise . See full list on freecodecamp. These are: indexOf() method @ANeves But . indexOf() method on the given string, passing it to the substring as a parameter. You can use the includes() method which will return the boolean value whether the substring is present in string or not. includes(searchTerm); // true. If the string does not contain the given substring, it returns -1. test(). How to check if a string contains a substring in Bash. Nov 6, 2021 · indexOf can be used to decide if the string, contains a substring or not. emsupirvwdfipbyhfeastnyxsywecicigwzsqwqhsmmsdjyvfnmbrqshljaaxsnmyhxgdc
Javascript string contains substring If the substring isn’t contained in the string, the method will return -1. Jun 14, 2016 · I have a string containing a person's first and last name such as John Doe. '; console. Feb 19, 2023 · Learn 4 approaches to check if a string contains a substring in JavaScript, using regular expression, includes(), indexOf() and a for loop. Several methods are used to check if a string contains another substring in Javascript. Feb 12, 2016 · To check the substring within the string you can use includes jQuery function like this var sub_str = "find" var main_str = "find me if you can" result = main_str. Let's discuss one of the most common tasks bellow. JavaScript Program to Check Whether a String Contains a Substring. If the string does not contain the substring, indexOf() returns -1. includes(); ES6 contains inbuilt method (includes) in String's prototype, which can be used to check if string contains another string or not. To use the ‘includes()’ method in JavaScript, you can simply call it on a string object with the substring as an argument. Just do the following myArray. includes(), introduced in ES6. 在编写 JavaScript 程序时，你可能需要检查一个字符串是否包含一个子字符串。子字符串是另一个字符串中的字符串。 具体来说，你可能需要检查一个单词是否包含特定字符或特定字符集。 Aug 24, 2024 · Here substring searches help analyze whether strings contain relevant keywords, conventions or formats. However, there are two other ways to search if a string contains a specified character or a phrase. contains(text, Dec 21, 2016 · I looks like your if logic here was if the first name doesn't contain "stream" or name 1 and 2 do not contain stream but your checking name 1 with lowercase "stream" and name 2 with uppercase "stream". in ITSM forum 2 weeks ago Applying complex Query in ITSM forum 2 weeks ago Using Image Variable Type to Put In Image Into Knowledge Base Article in ITSM forum 2 weeks ago May 25, 2023 · In this article, we'll explore different approaches to check whether a string contains a substring in JavaScript. Learn the canonical way, and also find out all the options you have, using plain JavaScript. includes which accepts a substring as an argument and will return a Nov 8, 2018 · Ask questions, find answers and collaborate at work with Stack Overflow for Teams. var a = 'good morning'; Here are the different ways to check if string contains substring in JavaScript. include() that we have covered so far, String. See examples, explanations, and code snippets from the Stack Overflow community. Mar 3, 2025 · In JavaScript, checking whether a string contains a specific substring is a common task. Apr 10, 2025 · Strings are useful for holding data that can be represented in text form. So if the search is larger or equal to 0, the substring exist. The includes method is a powerful tool for this purpose, allowing People here are making this waaay too difficult. The substring() method extracts characters from start to end (exclusive). It returns the index of the first occurrence of the specified substring within the string, or -1 if the substring is not found. Dec 3, 2024 · Here are the different ways to check if an array of strings contains a substring in JavaScript 1. May 20, 2022 · String. May 2, 2023 · Another way is to use the string indexOf() method, which returns the index of the first occurrence of the substring. I would like to convert this string to John D. The method searches the string for the substring in question and returns the index of the first occurrence if there is one. Mar 14, 2019 · So, you can easily check if a string contains a particular substring using the . includes("#") May 16, 2024 · The indexOf method in JavaScript is a simple and efficient way to check if a string contains a substring. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. Here's an example: Feb 15, 2011 · What is the regex for simply checking if a string contains a certain word (e. Oct 27, 2022 · 原文： How to Check if a String Contains a Substring in JavaScript. includes("hello", "hi", "howdy"); Imagine the comma states "or". Jul 27, 2022 · JavaScript ; String ; String contains substring ; Check if a string contains a substring in JavaScript String. If the expression and the string match it results in true and returns token ( which is the string the switch statement is operating on ). Using includes() and filter() method. Check String contains substring 1. displayed-result'). You can try to run the following code to check whether the string “Tutorialspoint: Free Video Tutorial” contains a substring “point” in or not. The 'every' method executes the provided callback function once for each element present in the array until it finds one where callback returns a falsy value (a value that becomes false when converted to a Boolean). replace() is regexp-based; if you pass in a string as the first argument, the regexp made from it will not include the ‘g’ (global) flag. Also, since you only want to match a sub-string, you'll need to remove the start and end anchors ^ and $. Sep 9, 2019 · To check if a string contains a substring in JavaScript: Call the String. Aug 25, 2023 · One of the simplest and most straightforward ways to check if a string contains a substring in JavaScript is by using the includes() method. The actual implementation comes from RegExp. The following shows you different ways of finding a substring in a JavaScript string: Using String. log(string. count = 12 Jan 8, 2018 · Need to loop an array of strings and check against with another string, which is passed in the string. includes() Method. includes() in JavaScript: Call the String. Use a regular expression to check if a string contains only alpha or alphanumeric characters in JavaScript. Apr 29, 2020 · I need to test whether the innerText of a element contains a substring using testcafe, but I'm not able to figure out the right way to do that. Jan 24, 2023 · Checking if String Contains a Substring in JavaScript To check if a string contains a substring in JavaScript, use the string. Unlike String. It is a simple and common task, but different languages handle it in different ways. This method returns a boolean value indicating whether the target string contains the specified substring. The first parameter is the substring to search for, and the second optional parameter is the Feb 13, 2024 · Hi @gunishi ,. It's a simple method that returns a boolean value depending on whether the string contains the substring or not. This method returns true if the substring is found in the string, and false otherwise. includes('To be')); One of the most basic tasks in any programming language is determining whether a string contains a given substring. Answer: Use the indexOf() Method. The String. Here's an example of how to use the includes() method:. : var str = "foobar"; var containsFoo = str. search(searchValue) searchValue is a regular expression or a string (will be converted to a regular expression). includes (substring, starting_point) array_name. search(), String. For example, if I apply a search for "on" for the string, "phones are good", it should return false. If start is greater than end, arguments are swapped: (4, 1) = (1, 4). The default position is 0. includes() str. 'Test')? dedicated "substring" methods tend to be faster in this case, because it Feb 2, 2024 · Use String. Follow our guide for simple and effective solutions. indexOf("the"); // position = 5 If the given string isn't present, indexOf will return -1. It returns true if the substring is found within the string, and false otherwise. If I change the observation string to a very long UTF-8 multibyte text, the results change drastically? Also, the results changed with change in position of substring in the observation string. Selector('. The substring() method does not change the original string. As you can see, a boolean value is returned since the string "stack" is a substring of stackabuse. var filterstrings = ['firststring','secondstring','thridstring']; var passedinstring = localSt Jul 27, 2011 · To replace substring. 3586. Let's have a look at how to check if a string contains a substring in JavaScript. Mar 21, 2022 · The best way one can check if a string contains a substring is to utilize the includes() method. Javascript match method accepts a regular expression as a parameter and if the string contains the given substring it will return an object with details of index, substring, input, and groups. If the returned value is not equal to -1, the string contains the substring. Normally, I would just use substring(0,1) on the last name variable, but how can I achieve this when the first and last name are one string with a space in between? Sep 16, 2010 · @EscapeNetscape: Nice to see a benchmark link. match() seems to check whether part of a string mat Jun 18, 2016 · Just wondering, is there a way to add multiple conditions to a . May 10, 2020 · JavaScript str. includes(), String. Unfortunately, JavaScript's built-in tools for doing so leave quite a bit to be desired. Javascript string substring check May 25, 2024 · Check if a string contains a substring in JavaScript. Jan 21, 2025 · The ‘includes()’ method is a simple and straightforward way to check if a string contains a specific substring. includes(substr); true. Dec 21, 2023 · Cómo usar el método includes() de JavaScript. findIndex() method to iterate over the array. var string = "foo"; var substring = "oo"; console. Using regex for a task like this gives you a lot more flexibility than with the previous methods where you can only check for a constant string. Learn how to use the includes() method to check if a string contains a specified string. Here's an example that demonstrates the usage of the includes() method: Aug 18, 2015 · You can then check for the presence of a string by using indexOf like so: var position = "Find the string". Jan 10, 2025 · The String constructor property in JavaScript is used to return the string constructor function for the object. substring case iterates over a potentially much smaller string. How to check if one string contains substring. prototype[Symbol. To do a case insensitive check if an array contains a string: Use the Array. Jan 2, 2025 · H ere are the different ways to check if an array of strings contains a substring in JavaScript. Example 2: With variable substring. [GFGTABS] JavaScript const a = Apr 24, 2019 · There are multiple ways to check if a string contains a substring in JavaScript. You can also include the position at which to begin searching the string for the substring. match](). Checking whether a string contains another string or not is very common in JavaScript and as well as in other programming languages. Using includes() method. See examples, code snippets and FAQs on this topic. substring also risks Voici une liste des possibilités actuelles: 1. JavaScript May 8, 2023 · Photo by Markus Spiske on Unsplash. Example. Jan 19, 2023 · Si vous utilisez un navigateur moderne ou une version avancée de node, on peut utiliser la méthode ES6 includes(). May 16, 2019 · There's two common ways to check whether a string contains a substring in JavaScript. indexOf(), String. The includes() method is arguably the most common way of checking if a string contains a substring. Whether you are a beginner or an experienced developer, this article will provide you valuable understanding into testing strings for substrings. Try Teams for free Explore Teams Apr 14, 2022 · 在本指南中，我们将学习如何使用includes() 方法来查找字符串中的子串；但首先，让我们讨论JavaScript中includes() 的语法。 语法。 string_name. indexOf() This is a three-step process: Call the indexOf method on the string, passing it the substring as a parameter. Nov 7, 2024 · JavaScript offers several methods to check whether a string contains a specific substring. Whether you need case-sensitive checks or prefer a flexible, case-insensitive approach, this guide has it covered. includes(sub_str) if result{ * Stuff todo if result found }else{ * Stuff todo if result not found } result true; // if you have sub string finder method separately and calling it from The substring() method extracts characters, between two indices (positions), from a string, and returns the substring. includes() to Check if a String Contains Substring in JavaScript Use String. (More on regex anchors) Your code becomes: Mar 13, 2025 · The implementation of String. The includes() method is the most simple and modern way to check if a string contains a specific substring. JavaScript offers different ways to perform this operation. It returns a Boolean value indicating whether the substring is found within the string. I tried array. JavaScript String substring() substring() is similar to slice(). May 1, 2018 · JavaScript offers many ways to check if a string contains a substring. includes() Mar 26, 2025 · There are subtle differences between the substring() and substr() methods, so you should be careful not to get them confused. 1. findIndex(element => element. indexOf('foo') >= 0; // true The indexOf method returns the character index where the first occurrence of the specified value is encountered, if not found, it returns -1 . According to npm trends, the popular string-includes substring search package receives over 2 million downloads per week in frameworks like React, Vue and Angular. substr()'s start index will wrap to the end of the string if it is negative, while substring() will clamp it to 0. Example-2: Using a substring and a starting position We can also check whether the target substring is located at a specific index. The simplest and fastest way to check whether a string contains a substring or not in JavaScript is the indexOf() method. I am kind of stuck on how to set it so that if I get three "True", I want to execute something, other I want it to do something else. Introduction to JavaScript String includes() method The includes() method performs a case-sensitive search and determines if a substring is included in a string: Oct 24, 2010 · /** Function that count occurrences of a substring in a string; * @param {String} string The string * @param {String} subString The sub string to search for * @param {Boolean} [allowOverlapping] Optional. includes(term, start) method, which checks if the string contains the substring. You can use either String. Jun 9, 2016 · I have multiple sub-strings that I want to find in a single string and if all three are found then do this, if not, do something else. May 24, 2010 · The test in this case is token. Depending on your needs, choose includes() for a straightforward, case-sensitive check, indexOf() to possibly retrieve the substring's position, or regular expressions for more complex matching requirements. org Nov 16, 2024 · Learn how to use includes(), indexOf() and regular expressions to check if one string is substring of another in JavaScript. Nov 24, 2009 · Learn how to check whether a string contains a substring in JavaScript using various methods, such as includes, indexOf, or KMP algorithm. Topic: JavaScript / jQuery Prev|Next. If you expect majority successes or only small inputs, . See examples, syntax, parameters, return value and browser support for this ECMAScript6 feature. How to check whether a string contains a substring in JavaScript? By using the following methods, you can easily check whether a string contains a substring in JavaScript: Sep 15, 2023 · In this article, we will discuss the JavaScript Test if String Contains Substring. Apr 11, 2025 · This method takes two parameters – the substring that you want to search for, and an optional parameter that specifies the starting point of the search. And, it should return true for "keep it on the table". Aug 18, 2021 · To check if a string contains a substring in JavaScript the easiest way is to use String. How to Check Whether a String Contains a Substring in JavaScript. var position = "Find the string". See examples, syntax and pros and cons of each method. indexOf(substring) !== -1); // true Aug 26, 2019 · If we look at the docs for String. The indexOf() method is case-sensitive and accepts two parameters. search() accepts a regular expression as its parameter. indexOf("notFound"); // position = -1 You can then use this in an if statement like so Sep 6, 2023 · If all you need to do is get a boolean value indicating if the substring is in another string, then this is what you'll want to use. Summary: in this tutorial, you will learn how to use the JavaScript String includes() method to check if a string contains a substring. Jan 9, 2023 · I want to use JavaScript (I can also use jQuery) to do check whether a string matches the regex ^([a-z0-9]{5,})$, and get a true or false result. . Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. JavaScript · March 24, 2024 Check if a JavaScript string contains only alpha or alphanumeric characters. includes()provides the most simple and popular way to check if a string contains a Apr 7, 2011 · Pretty straight forward. indexOf() method. [GFGTABS] JavaScript const a = Sep 22, 2022 · When you’re testing if a string contains a specific substring, you might be inclined to use a method like indexOf(). var str = 'To be, or not to be, that is the question. indexOf() method, str. We will see the built-in May 22, 2015 · You don't really need jQuery for such a simple thing, you can simply use the indexOf method of String objects, e. To understand this example, you should have the knowledge of the following JavaScript programming topics: JavaScript String; Javascript String includes() JavaScript String indexOf() Oct 2, 2012 · In the first alert(), JavaScript returned "-1" - in other words, indexOf() did not find a match: this is simply because "JavaScript" is in lowercase in the first string, and properly capitalized in the second. includes("substring")) findIndex() is an ES6 higher order method that iterates through the elements of an array and returns the index of the first element that matches some criteria (provided as a function). match doesn't do much other than calling the Symbol. However, for more flexible testing and conditions, using regular expressions Jan 7, 2021 · In this tutorial, we discussed the basics of strings in JavaScript. search() is another method that you can use to check if a string contains another word, substring or character inside the main string. # Ignoring case Check if Array contains String - Array. match(/spo/) which states the match the string held in token against the regex expression /spo/ ( which is the literal string spo in this case ). ES5 et plus indexOf Feb 20, 2024 · Here are the different ways to check if an array of strings contains a substring in JavaScript 1. Other search methods you can consider include: May 30, 2024 · JavaScript is an incredibly versatile language, and working with strings is one of its many strengths. As you can see, the basic syntax allows you to easily check if a string contains a substring in JavaScript. replace('-',''); Output: -----check Jquery removes first '-' from my text. Jun 8, 2017 · I have an array like this: array = ["123", "456", "#123"] I want to find the element which contains the substring "#". We will create an array of strings, then use includes() and filter() methods to check whether the array elements contain a sub-string. search(substring) to check if a string contains your substring. it looks like you just want both names not to contain stream, this can be much more easily performed like this. Compare the returned value to -1 . includes() we can see it takes a string, not a regular expression. ¿Qué es el método includes() de JavaScript? Veamos su sintaxis. substring is likely faster. But not working for me var str='------check'; str. I'm interested in finding if a string contains a word. Using the includes() method. This operation is useful for various applications, such as searching for keywords in user input, filtering data, or validating form inputs. [GFGTABS] JavaScript const a = Mar 1, 2024 · We just need the strings to be in the same case to be able to determine if the substring is contained in the string. Checking if a string contains a substring is one of the most common tasks in any programming language. Mar 31, 2025 · Check Whether String Contains Substring. To check if a string contains substring JavaScript, we commonly refer to the includes() method because of its targeted design towards a string and the letters search. Using includes() Method. May 25, 2016 · For reducing the function you can use every() and indexOf() methods. Works perfectly fine when search term is a variable. If the separator is omitted, the returned array will contain the whole string in index [0]. Sep 8, 2019 · To check if a string contains a substring using String. Using includes() You can use includes() function to check if a string contains a substring or not. includes() The most straightforward substring search option is String. (ES6) includes - aller à la réponse var string = "foo", substring = "oo"; string. indexOf() to Check if a String Contains Substring in JavaScript This tutorial teaches how to check if a string contains a substring in JavaScript. lastIndexOf on a long string that's going to return false is going to iterate over the entire string (O(N)), whereas the . innerText = '12 results' Selector('user-details'). To check if a string contains substring or not, use the Javascript match method. This method returns the index or position of the first occurrence of substring within Syntax string. Cómo usar el método indexOf() de JavaScript. String. match(), regular expressions, or 3rd-party library like Lodash. El método includes() de JavaScript se introdujo con ES6 y la forma más común y moderna de verificar si una cadena contiene un caracter específico o una serie de caracteres. It is often used in arrays, and the same can be applied with strings. includes (element, starting_point) 在JavaScript中include()方法需要两个参数。 substring/element。第一个 Methods To Check for JavaScript String Contains. May 4, 2016 · Is there a way in lodash to check if a strings contains one of the values from an array? For example: var text = 'this is some sample text'; var values = ['sample', 'anything']; _. How to check whether a string contains a substring in JavaScript? 3627. includes(substring); 2. La méthode includes() renvoie true si la sous-chaîne se trouve dans la chaîne de caractères qu’on teste. The function which is returned by this property is just the reference to this function, not a string containing the function's name. Oct 18, 2022 · Another way to check if a string contains a substring in JavaScript is to use the string. The indexOf method would return -1 if the substring is not present in the string. Let us say you have the following string. After that, we discussed three ways in which you can check if a string contains a substring in JavaScript: using includes(), indexOf(), and regex. I need to remove One of the most basic tasks in any programming language is determining whether a string contains a given substring. Oct 21, 2022 · The code above returns 8. Dec 8, 2021 · Hi, in this tutorial, we are going to talk about 7 Ways to check if a string contains a substring or not in javascript. includes() method. search() method. includes() method on the string. there's not much that can be done about that without doing much more detailed inspection of the strings. includes method, for example: var value = str. Using includes() and filter() methodWe will create an array of strings, then use includes() and filter() methods to check whether the array elements contain a sub-string. Here's how you can do it: Using indexOf(): You can use the indexOf() method to check if a string contains a specific substring. findIndex. Sep 6, 2023 · One of the more useful and powerful ways to check for a substring is to use regular expressions, or regex. In javascript, I need to check if a string contains any substrings held in an array. First of all, let's take a look at using String. log(str. It takes a substring as an argument and returns a boolean value, which is exactly what we need. Mar 13, 2025 · The includes() method of String values performs a case-sensitive search to determine whether a given string may be found within this string, returning true or false as appropriate. indexOf() and String. If there is a substring it returns the index it was found (some number from 0 to n), otherwise if it's not found it returns -1. The includes() method is a simple and straightforward way to check if a string contains a substring. includes(substr) . The first parameter is the string to search for, and the second optional parameter specifies the position from which to search. Remove duplicates from the string variable type. Checking whether a string contains a specific substring is a common task in JavaScript. This option is essential if you want to replace all occurances of the search string (which is usually what you want). Dec 2, 2024 · Here are the different ways to check if an array of strings contains a substring in JavaScript 1. If the string contains the substring, indexOf() returns the index of the first occurrence of the substring. . let searchTerm = "world"; let str = "Hello world!"; str. Dec 2, 2024 · Here are the different methods to check whether a string contains a substring in JavaScript. g. match method of the argument with the string as the first parameter. Dec 6, 2022 · It is true that the string JavaScript string contains is easy contains the string substring. Whether you're building a web application, processing data, or just playing around with code, you may need to check if a string contains a specific substring. If the string does not contain the substring then it will return null. Instead, try RegExp. Jun 10, 2022 · Through this tutorial, you will learn how to check whether a string contains a character or substrings in javascript using the javaScript include(), indexOf() method. For example you can use string. Jun 24, 2024 · Learn the best methods to check if a string contains a substring in JavaScript. It works like this: > let str = 'stackabuse'; > let substr = 'stack'; > str. In script, you can check if a string contains a specific substring using the indexOf() method or a regular expression. The two parameters of substr() are start and length, while for substring(), they are start and end. Pass the substring as a parameter, e. prototype. The more modern way is the String#includes() function. Conditionally check if the returned value is not equal to -1. This built-in function on the String object checks if a string contains a substring. Some of the most-used operations on strings are to check their length, to build and concatenate them using the + and += string operators, checking for the existence or location of substrings with the indexOf() method, or extracting substrings with the substring() method. Checks if str contains "world", which it does so returns true. The JavaScript number constructor, string constructor, Aug 14, 2016 · When working with JavaScript, determining whether a string contains a specific substring is a common task. Jan 26, 2010 · Javascript seems to use locale "C" for string comparisons so the resulting ordering will be ugly if the strings contain other than ASCII letters. prototype's indexOf method. Understanding JavaScript String Basics Aug 16, 2014 · Note that there are plenty of methods that allow you to do this. Mar 1, 2024 · # Check if a String contains a Substring with String. lastIndexOf is likely faster - otherwise . See full list on freecodecamp. These are: indexOf() method @ANeves But . indexOf() method on the given string, passing it to the substring as a parameter. You can use the includes() method which will return the boolean value whether the substring is present in string or not. includes(searchTerm); // true. If the string does not contain the given substring, it returns -1. test(). How to check if a string contains a substring in Bash. Nov 6, 2021 · indexOf can be used to decide if the string, contains a substring or not. emsup irvwd fipb yhfe ast nyxsy weci cigwzs qwqhs mmsdjy vfnm brq shljaa xsn myhxgdc