How to Check Whether a String Contains a Substring in JavaScript

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JavaScript provides a number of ways to check whether a string contains a substring. In this blog post, we will discuss three of the most common methods:

• The includes() method
• The indexOf() method

The includes() Method

The includes() method was introduced in ES6, and it is the most concise and efficient way to check whether a string contains a substring.

The includes() method takes two arguments:

• The first argument is the substring you want to check for
• The second argument is the optional index at which you want to start the search.

If the substring is found, the includes() method returns true; otherwise, it returns false.

For example, the following code checks whether the string "hello world" contains the substring "world":

Code snippet

const str = "hello world";
const substring = "world";
const result = str.includes(substring);
console.log(result); // true

The indexOf() Method

The indexOf() method takes two arguments:

• The first argument is the substring you want to check for