Learn JavaScript – How To Check if One String Contains Another Substring?

javascript string

JavaScript is one of the easiest programming languages to learn. If you are confused on how to check if one string contains another substring in JavaScript, then you have come to the right place. There are many ways one can achieve the desired result, so let’s go through them one by one.

The most common method: string.indexOf()


The best way to find a substring from a string is to use the indexOf() function. If you noticed, the indexOf() method simply tests if the substring is present or not. If it is present, it will return the starting index of the substring; if not, it will return -1. We can use the behavior of the indexOf() method to find a substring. All we need to do is set a condition to check for the return value.

RegExp.test() method

Next, we can use the RegExp.test() method to find a substring. This method returns a boolean and hence is much easier to use. In comparison to the indexOf() method, it returns direct true or false results and can therefore be a good alternative.

While RegExp.test() is a great method to use, special characters can be a problem.


The last method is String.contains(). It directly checks if the substring is present or not and returns a boolean value. It is available after ECMAScript 6, and hence needs to be used with caution.

Do you have anything to add to the tutorial? If yes, don’t forget to comment below and let us know.

You can also check on our website for videos about JavaScript. Below are some examples:

  • Functional JavaScript (part 10) – JavaScript

  • JSbroadcast.com – Hacking in MEAN Stack (part 32) – JavaScript

You can also follow some of our broadcasters who program in JavaScript as below:



Another cool way to find out interesting things about JavaScript is to access our project page!

About author

About Author Dr. Michael Jurgen Garbade is the founder of LiveEdu.TV, Kyuda, Education Ecosystem. He is future Venture Capitalist, Future Politician and always on the lookout for the Next Big Challenge. Obtained Masters in business administration and physics, and a Ph.D. in finance with professional work experience in high-paced environments at Fortune 500 companies like Amazon and General Electric. Expertize: Python, PHP, Sencha Touch & C++, SEO, Finance, Strategy & E-commerce. He speaks English and German and has worked in the US, Europe, and Asia. At Education Ecosystem he is the CEO and runs business operations.
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