Fastest Way To Check A String Contain Another Substring In Javascript

When you're coding in JavaScript, one common task is to check if a string contains another substring. This might sound like a simple task, but there are several ways to go about it. In this article, we'll explore the fastest way to check if a string contains a specific substring in JavaScript, so you can efficiently handle this task in your projects.

One of the quickest and most efficient methods to check for a substring in a string in JavaScript is by using the `includes()` method. This method is available for strings in JavaScript and returns `true` if the specified substring is found within the string, otherwise it returns `false`.

Here's a basic example of how you can use the `includes()` method to check if a string contains a specific substring:

const mainString = "Welcome to JavaScript tutorials";
const subString = "JavaScript";

if(mainString.includes(subString)) {
    console.log("The main string contains the substring");
} else {
    console.log("The main string does not contain the substring");
}

In this example, we have a main string that we want to check for the presence of the substring "JavaScript". We use the `includes()` method to quickly and efficiently check if the substring exists within the main string.

Another powerful method for checking substrings in JavaScript is the `indexOf()` method. This method returns the position of the first occurrence of a specified substring within a string. If the substring is not found, it returns -1.

Here's an example demonstrating the usage of the `indexOf()` method:

const mainString = "Hello, how are you?";
const subString = "how";

if(mainString.indexOf(subString) !== -1) {
    console.log("The main string contains the substring at position " + mainString.indexOf(subString));
} else {
    console.log("The main string does not contain the substring");
}

In this snippet, we use the `indexOf()` method to find the position of the substring "how" within the main string. We then check if the index returned is not equal to -1, indicating that the substring exists in the main string.

Both the `includes()` and `indexOf()` methods are efficient ways to check for substrings in JavaScript. However, the `includes()` method is ideal for simple checks where you only need to confirm if a substring exists, while the `indexOf()` method provides more flexibility by returning the index of the substring if found.

By using these methods wisely in your JavaScript code, you can efficiently check for the presence of substrings in strings, making your code more robust and performant. So, next time you need to check if a string contains a specific substring, remember to leverage the power of `includes()` and `indexOf()` methods to get the job done swiftly and effectively.