How Do I Check If String Contains Substring?

As a JavaScript developer, you may often come across the need to check if a string contains a specific substring. Fortunately, JavaScript provides several ways to accomplish this task. In this article, we will explore three different approaches to check if a string contains a substring.

1. Using the includes() method

The includes() method is a built-in JavaScript method that returns true if a string contains a specified substring, and false otherwise.

const str = "Hello, world!";
const substring = "world";

console.log(str.includes(substring)); // Output: true

2. Using the indexOf() method

The indexOf() method returns the index of the first occurrence of a specified substring within a string. If the substring is not found, it returns -1.

const str = "Hello, world!";
const substring = "world";

console.log(str.indexOf(substring) !== -1); // Output: true

3. Using regular expressions (RegExp)

Regular expressions provide a powerful way to search for patterns within strings. By using the test() method of a regular expression, we can check if a string contains a specific substring.

const str = "Hello, world!";
const substring = "world";
const regex = new RegExp(substring);

console.log(regex.test(str)); // Output: true

These are three different approaches you can use to check if a string contains a substring in JavaScript. Choose the one that best fits your needs and enjoy the flexibility and power of JavaScript!

Do you have any other JavaScript-related questions? Feel free to ask in the comments below!