SearchString - Required, the character/ string to search.Although there are other methods that can be used to find substrings, the startsWith() method is specifically used to check the start of a string. This method is commonly used to check if the entered string contains a substring. The method returns a boolean true in case the string starts with the specified characters. The JavaScript startsWith method is used to determine whether a string starts with a character or a particular string. Table of Contents - JavaScript startsWith(): We break down the code with an example to help you understand the concept better. In this short tutorial, we look at how to use the JavaScript startsWith method. How to use the JavaScript startsWith() method? indexOf ( 'nice', 3 ) != - 1 //false 'a nice string'. indexOf ( 'nice' ) != - 1 //true 'a nice string'. Like includes(), the second parameters sets the starting point: 'a nice string'. If the substring is found, it returns the index of the character that starts the string. Pre-ES6, the common way to check if a string contains a substring was to use indexOf, which is a string method that return -1 if the string does not contain the substring. includes ( 'nice', 2 ) //true Pre-ES6 alternative to includes(): indexOf() includes ( 'nice', 3 ) //false 'a nice string'. includes ( 'nice' ) //true 'a nice string'. Includes() also accepts an optional second parameter, an integer which indicates the position where to start searching for: 'a nice string'. To use it on all browsers, use Polyfill.io or another dedicated polyfill. It’s supported in all modern browsers except Internet Explorer: This method was introduced in ES6/ES2015. The most simple one, and also the canonical one going forward, is using the includes() method on a string: 'a nice string'. JavaScript offers different ways to perform this operation. Learn the canonical way, and also find out all the options you have, using plain JavaScriptĬhecking if a string contains a substring is one of the most common tasks in any programming language. JavaScript offers many ways to check if a string contains a substring.
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