Javascript string contains substring.

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