This is because the name of the method is literal. The includes() method is arguably the most common way of checking if a string contains a substring. After that, we discussed three ways in which you can check if a string contains a substring in JavaScript: using includes(), indexOf(), and regex. In this tutorial, we discussed the basics of strings in JavaScript. If you’re looking to learn more about regex and test out your regex, check out RegExr. The RegExp.test() method is not recommended for beginners who have not yet learned about Regex. If you’re performing a simple search and have no need for advanced string functions, using includes() or indexOf() may be a better approach. The more statements you add to your regex rules, the longer your search will take. The downside to regex is that it can be slower to run depending on what rules you use. This is because “JavaScript” is in our “example” string.

If the specified string does not contain the characters for which you are looking, includes() will return “false.” If the string contains certain characters, the method will return “true.” The JavaScript includes() method, introduced in ES6, determines whether a string contains the characters you have passed into the method.

In this tutorial, we’re going to discuss methods you can use to check if a JavaScript string contains another string using these three approaches. There are three methods for checking if a JavaScript string contains another character or sequence of characters:

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I assume V8 (and other engines) can optimise this function. I'll have a go.ĭesign notes: I wanted to minimize memory usage, and therefore improve speed - so there is no copying/mutating of strings. It's 2016, and there's no clear way of how to do this? I was hoping for some copypasta.

Js includes