How to check if string contains a substring in JavaScript?

Published: August 6, 2021Last updated: August 6, 2021contains, JavaScript, string, substring

The ability to check a string contains a substring should have been standard in JavaScript. Prior to ES6, there were no standard functions to do this check.

The modern JavaScript ECMAScript 6 introduces String#includes for checking that. In this article, we tried to compile most of the ways to check a substring exists inside a string.

Using String#includes:

ECMAScript 6 introduces String#includes, it checks a substring is included inside a string or not. It is widely supported by all browsers except IE:

// Approach #1:
const str = 'World Health Organization';
console.log(str.includes('Health')); // true

Using String#indexOf:

String#indexOf is quite an old string method that we can use to checks a substring is included inside a string or not. It is widely supported by all browsers except IE8:

// Approach #2:
const str = 'World Health Organization';
console.log(str.indexOf('Health') > -1); // true

Using test method:

test() can be used to checks a substring is included inside a string or not.

// Approach #3:
const str = 'World Health Organization';
console.log(/Health/i.test(str)); // true

Using String#search:

String#search can be used to checks a substring is included inside a string or not. It is widely supported by all browsers:

// Approach #4:
const str = 'World Health Organization';
console.log(str.search('Health') > -1); // true

Using String#match:

String#match can be used to checks a substring is included inside a string or not. It is widely supported by all browsers:

// Approach #5:
const str = 'World Health Organization';
console.log(str.match('Health') !== null); // true

Using String#includes:

Using String#indexOf:

Using test method:

Using String#search:

Using String#match:

You May Also Like