In this article, We’ll see how to check a string contains a substring in javascript?

In ES6, we’ll use String.prototype.includes to find a substring in a string

The includes() method determines whether one string may be found within another string, returning true or false as appropriate.

Below an example using ES6 to find string contains a substring

var sentence = 'India is a great country.';
var word     = 'great';
console.log(`The word "${word}" ${sentence.includes(word)? 'is' : 'is not'} in the sentence`); // expected output: "The word "great" is in the sentence"

In an ES5 or older environments, we’ll use String.prototype.indexOf returns the index of a substring (or -1 if not found):

Below an example using ES5 or older environments to find string contains a substring

if (sentence.indexOf(word) !== -1)
console.log('The word "' + word + '" is in the sentence');
 else
console.log('The word "' + word + '" is not in the sentence');

That’s it!. Please share your thoughts or suggestions in the comments below.