Javascript string contains substring.

Javascript string contains substring Whether you need case-sensitive checks or prefer a flexible, case-insensitive approach, this guide has it covered. You can use the includes() method which will return the boolean value whether the substring is present in string or not. JavaScript Program to Check Whether 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. 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 ). includes(); ES6 contains inbuilt method (includes) in String's prototype, which can be used to check if string contains another string or not. Pass the substring as a parameter, e. The indexOf() method is case-sensitive and accepts two parameters. 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. 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. includes(), introduced in ES6. 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 . Learn how to use the includes() method to check if a string contains a specified string. Using includes() method. : var str = "foobar"; var containsFoo = str. If the expression and the string match it results in true and returns token ( which is the string the switch statement is operating on ). JavaScript String substring() substring() is similar to slice(). (ES6) includes - aller à la réponse var string = "foo", substring = "oo"; string. 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. 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. include() that we have covered so far, String. Summary: in this tutorial, you will learn how to use the JavaScript String includes() method to check if a string contains a substring. See examples, code snippets and FAQs on this topic. Here's how you can do it: Using indexOf(): You can use the indexOf() method to check if a string contains a specific substring. The actual implementation comes from RegExp. lastIndexOf on a long string that's going to return false is going to iterate over the entire string (O(N)), whereas the . How to check whether a string contains a substring in JavaScript? 3627. Let us say you have the following string. 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. 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). It takes a substring as an argument and returns a boolean value, which is exactly what we need. lastIndexOf is likely faster - otherwise . Example. includes() to Check if a String Contains Substring in JavaScript Use String. Dec 3, 2024 · Here are the different ways to check if an array of strings contains a substring in JavaScript 1. If the returned value is not equal to -1, the string contains the substring. How to check if a string contains a substring in Bash. 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. See full list on freecodecamp. However, there are two other ways to search if a string contains a specified character or a phrase. Checking whether a string contains a specific substring is a common task in JavaScript. Jan 19, 2023 · Si vous utilisez un navigateur moderne ou une version avancée de node, on peut utiliser la méthode ES6 includes(). 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. prototype's indexOf method. String. May 25, 2016 · For reducing the function you can use every() and indexOf() methods. Several methods are used to check if a string contains another substring in Javascript. search(searchValue) searchValue is a regular expression or a string (will be converted to a regular expression). Using the includes() method. Dec 6, 2022 · It is true that the string JavaScript string contains is easy contains the string substring. includes()provides the most simple and popular way to check if a string contains a Apr 7, 2011 · Pretty straight forward. Use a regular expression to check if a string contains only alpha or alphanumeric characters in JavaScript. Compare the returned value to -1 . includes() in JavaScript: Call the String. As you can see, the basic syntax allows you to easily check if a string contains a substring in JavaScript. 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. May 24, 2010 · The test in this case is token. var a = 'good morning'; Here are the different ways to check if string contains substring in JavaScript. If start is greater than end, arguments are swapped: (4, 1) = (1, 4). The includes method is a powerful tool for this purpose, allowing People here are making this waaay too difficult. Sep 8, 2019 · To check if a string contains a substring using String. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. findIndex. 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. search() method. The includes() method is arguably the most common way of checking if a string contains a substring. substring is likely faster. match(), regular expressions, or 3rd-party library like Lodash. 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. JavaScript May 8, 2023 · Photo by Markus Spiske on Unsplash. Jul 27, 2022 · JavaScript ; String ; String contains substring ; Check if a string contains a substring in JavaScript String. As you can see, a boolean value is returned since the string "stack" is a substring of stackabuse. search(), String. 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. Jan 2, 2025 · H ere are the different ways to check if an array of strings contains a substring in JavaScript. See examples, explanations, and code snippets from the Stack Overflow community. It returns true if the substring is found within the string, and false otherwise. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. Understanding JavaScript String Basics Aug 16, 2014 · Note that there are plenty of methods that allow you to do this. This built-in function on the String object checks if a string contains a substring. includes() method on the string. It returns a Boolean value indicating whether the substring is found within the string. Javascript string substring check May 25, 2024 · Check if a string contains a substring in JavaScript. match method of the argument with the string as the first parameter. Cómo usar el método indexOf() de JavaScript. includes() Mar 26, 2025 · There are subtle differences between the substring() and substr() methods, so you should be careful not to get them confused. JavaScript offers different ways to perform this operation. var string = "foo"; var substring = "oo"; console. It returns the index of the first occurrence of the specified substring within the string, or -1 if the substring is not found. indexOf() and String. The first parameter is the substring to search for, and the second optional parameter is the Feb 13, 2024 · Hi @gunishi ,. If the separator is omitted, the returned array will contain the whole string in index [0]. . Example-2: Using a substring and a starting position We can also check whether the target substring is located at a specific index. Whether you are a beginner or an experienced developer, this article will provide you valuable understanding into testing strings for substrings. Using includes() You can use includes() function to check if a string contains a substring or not. 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". First of all, let's take a look at using String. 1. # Ignoring case Check if Array contains String - Array. indexOf() This is a three-step process: Call the indexOf method on the string, passing it the substring as a parameter. Unfortunately, JavaScript's built-in tools for doing so leave quite a bit to be desired. 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. It is a simple and common task, but different languages handle it in different ways. Mar 3, 2025 · In JavaScript, checking whether a string contains a specific substring is a common task. includes(substring); 2. Also, since you only want to match a sub-string, you'll need to remove the start and end anchors ^ and $. log(str. For example you can use string. But not working for me var str='------check'; str. The String. let searchTerm = "world"; let str = "Hello world!"; str. indexOf("the"); // position = 5 If the given string isn't present, indexOf will return -1. displayed-result'). search() is another method that you can use to check if a string contains another word, substring or character inside the main string. includes(term, start) method, which checks if the string contains the substring. The substring() method extracts characters from start to end (exclusive). In javascript, I need to check if a string contains any substrings held in an array. 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. Dec 2, 2024 · Here are the different ways to check if an array of strings contains a substring in JavaScript 1. 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. You can also include the position at which to begin searching the string for the substring. Apr 10, 2025 · Strings are useful for holding data that can be represented in text form. Answer: Use the indexOf() Method. 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". May 2, 2023 · Another way is to use the string indexOf() method, which returns the index of the first occurrence of the substring. Check String contains substring 1. However, for more flexible testing and conditions, using regular expressions Jan 7, 2021 · In this tutorial, we discussed the basics of strings in JavaScript. And, it should return true for "keep it on the table". 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 . The two parameters of substr() are start and length, while for substring(), they are start and end. 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. This method returns a boolean value indicating whether the target string contains the specified substring. This method returns the index or position of the first occurrence of substring within Syntax string. 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. it looks like you just want both names not to contain stream, this can be much more easily performed like this. If you expect majority successes or only small inputs, . Checking whether a string contains another string or not is very common in JavaScript and as well as in other programming languages. indexOf() method, str. includes() method. match doesn't do much other than calling the Symbol. count = 12 Jan 8, 2018 · Need to loop an array of strings and check against with another string, which is passed in the string. log(string. It's a simple method that returns a boolean value depending on whether the string contains the substring or not. '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() method on the given string, passing it to the substring as a parameter. test(). [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. Works perfectly fine when search term is a variable. includes("hello", "hi", "howdy"); Imagine the comma states "or". includes() Method. var filterstrings = ['firststring','secondstring','thridstring']; var passedinstring = localSt Jul 27, 2011 · To replace substring. Example 2: With variable substring. It works like this: > let str = 'stackabuse'; > let substr = 'stack'; > str. var str = 'To be, or not to be, that is the question. I need to remove One of the most basic tasks in any programming language is determining whether a string contains a given substring. To use the ‘includes()’ method in JavaScript, you can simply call it on a string object with the substring as an argument. Jan 10, 2025 · The String constructor property in JavaScript is used to return the string constructor function for the object. This operation is useful for various applications, such as searching for keywords in user input, filtering data, or validating form inputs. The simplest and fastest way to check whether a string contains a substring or not in JavaScript is the indexOf() method. Dec 2, 2024 · Here are the different methods to check whether a string contains a substring in JavaScript. innerText = '12 results' Selector('user-details'). indexOf() to Check if a String Contains Substring in JavaScript This tutorial teaches how to check if a string contains a substring in JavaScript. 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. includes(substr); true. Sep 9, 2019 · To check if a string contains a substring in JavaScript: Call the String. includes(searchTerm); // true. includes (substring, starting_point) array_name. The following shows you different ways of finding a substring in a JavaScript string: Using String. See examples, syntax, parameters, return value and browser support for this ECMAScript6 feature. 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. Jun 24, 2024 · Learn the best methods to check if a string contains a substring in JavaScript. Topic: JavaScript / jQuery Prev|Next. Instead, try RegExp. May 16, 2019 · There's two common ways to check whether a string contains a substring in JavaScript. After that, we discussed three ways in which you can check if a string contains a substring in JavaScript: using includes(), indexOf(), and regex. g. 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. The substring() method does not change the original string. 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). To check if a string contains substring or not, use the Javascript match method. 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. You can try to run the following code to check whether the string “Tutorialspoint: Free Video Tutorial” contains a substring “point” in or not. Nov 6, 2021 · indexOf can be used to decide if the string, contains a substring or not. includes(), String. The more modern way is the String#includes() function. 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. [GFGTABS] JavaScript const a = Apr 24, 2019 · There are multiple ways to check if a string contains a substring in JavaScript. 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. includes("#") May 16, 2024 · The indexOf method in JavaScript is a simple and efficient way to check if a string contains a substring. If the substring isn’t contained in the string, the method will return -1. If the string does not contain the substring, indexOf() returns -1. includes('To be')); One of the most basic tasks in any programming language is determining whether a string contains a given substring. If the string does not contain the given substring, it returns -1. Oct 27, 2022 · 原文： How to Check if a String Contains a Substring in JavaScript. 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. Using includes() Method. Let's discuss one of the most common tasks bellow. '; console. The includes() method is a simple and straightforward way to check if a string contains a 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. Mar 1, 2024 · # Check if a String contains a Substring with String. Jan 21, 2025 · The ‘includes()’ method is a simple and straightforward way to check if a string contains a specific substring. Unlike String. This option is essential if you want to replace all occurances of the search string (which is usually what you want). You can use either String. Sep 6, 2023 · One of the more useful and powerful ways to check for a substring is to use regular expressions, or regex. I would like to convert this string to John D. If the string contains the substring, indexOf() returns the index of the first occurrence of the substring. May 10, 2020 · JavaScript str. Selector('. indexOf(substring) !== -1); // true Aug 26, 2019 · If we look at the docs for String. 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. Here's an example: Feb 15, 2011 · What is the regex for simply checking if a string contains a certain word (e. ¿Qué es el método includes() de JavaScript? Veamos su sintaxis. The default position is 0. We will create an array of strings, then use includes() and filter() methods to check whether the array elements contain a sub-string. Jun 8, 2017 · I have an array like this: array = ["123", "456", "#123"] I want to find the element which contains the substring "#". substring case iterates over a potentially much smaller string. org Nov 16, 2024 · Learn how to use includes(), indexOf() and regular expressions to check if one string is substring of another in JavaScript. To do a case insensitive check if an array contains a string: Use the Array. Jan 24, 2023 · Checking if String Contains a Substring in JavaScript To check if a string contains a substring in JavaScript, use the string. 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. La méthode includes() renvoie true si la sous-chaîne se trouve dans la chaîne de caractères qu’on teste. Using includes() and filter() method. 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. Conditionally check if the returned value is not equal to -1. Let's have a look at how to check if a string contains a substring in JavaScript. search(substring) to check if a string contains your substring. match](). Learn the canonical way, and also find out all the options you have, using plain JavaScript. indexOf() method. prototype[Symbol. Mar 21, 2022 · The best way one can check if a string contains a substring is to utilize the includes() method. 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. 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. Checks if str contains "world", which it does so returns true. Here's an example of how to use the includes() method:. findIndex(element => element. 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. Aug 18, 2021 · To check if a string contains a substring in JavaScript the easiest way is to use String. . How to check if one string contains substring. Mar 14, 2019 · So, you can easily check if a string contains a particular substring using the . prototype. includes() The most straightforward substring search option is String. See examples, syntax and pros and cons of each method. includes method, for example: var value = str. So if the search is larger or equal to 0, the substring exist. Mar 31, 2025 · Check Whether String Contains Substring. var position = "Find the string". 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. In script, you can check if a string contains a specific substring using the indexOf() method or a regular expression. 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. [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(). The method searches the string for the substring in question and returns the index of the first occurrence if there is one. 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. 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. The function which is returned by this property is just the reference to this function, not a string containing the function's name. there's not much that can be done about that without doing much more detailed inspection of the strings. This method returns true if the substring is found in the string, and false otherwise. May 20, 2022 · String. 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. JavaScript · March 24, 2024 Check if a JavaScript string contains only alpha or alphanumeric characters. substring also risks Voici une liste des possibilités actuelles: 1. search() accepts a regular expression as its parameter. 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']; _. Dec 21, 2023 · Cómo usar el método includes() de JavaScript. substr()'s start index will wrap to the end of the string if it is negative, while substring() will clamp it to 0. It is often used in arrays, and the same can be applied with strings. The first parameter is the string to search for, and the second optional parameter specifies the position from which to search. Jun 14, 2016 · I have a string containing a person's first and last name such as John Doe. Checking if a string contains a substring is one of the most common tasks in any programming language. Remove duplicates from the string variable type. Just do the following myArray. indexOf(), String. includes() str. The includes() method is the most simple and modern way to check if a string contains a specific substring. The indexOf method would return -1 if the substring is not present in the string. Oct 21, 2022 · The code above returns 8. includes(substr) . Nov 7, 2024 · JavaScript offers several methods to check whether a string contains a specific substring. 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. findIndex() method to iterate over the array. 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. May 1, 2018 · JavaScript offers many ways to check if a string contains a substring. Oct 18, 2022 · Another way to check if a string contains a substring in JavaScript is to use the string. These are: indexOf() method @ANeves But . replace('-',''); Output: -----check Jquery removes first '-' from my text. includes() we can see it takes a string, not a regular expression. If the string does not contain the substring then it will return null. I tried array. (More on regex anchors) Your code becomes: Mar 13, 2025 · The implementation of String. For example, if I apply a search for "on" for the string, "phones are good", it should return false. 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. I'm interested in finding if a string contains a word. How to Check Whether a String Contains a Substring in JavaScript. 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. 3586. jgl ezrmw pvtwinpa mtdi mni wtxyr dds pqfgj cipad tbrai hvump bhdv xczb aywbi glse