Learn how to find if a string contains a substring in javascript using indexOf, Includes, and Search method in javascript.
If you’re working with strings in JavaScript, you may need to check if a particular substring exists within a given string.
Fortunately, JavaScript provides several methods that allow you to easily check for the presence of a substring.
In this context, we’ll explore the three most commonly used methods to check if a string contains a substring in JavaScript:
indexOf()includes()search().
These methods can be used to search for a single character, a word, or a group of characters in a string.
1. Using IndexOf() Method
indexOf method returns the index of the first occurrence of a specified substring within a given string.
If the substring is not found, the method returns -1.
The indexOf() method is a commonly used way to check if a string contains a substring in JavaScript.
const string = "Hello world!";
const substring = "world";
if (string.indexOf(substring) !== -1) {
console.log("Substring found!");
} else {
console.log("Substring not found.");
}
2. Using includes() method
Includes method returns a boolean value indicating whether a specified substring is present within a given string or not.
If the substring is found, the method returns true; if not, it returns false.
The includes() method is similar to the indexOf() method but returns a Boolean value rather than an index.
const string = "Hello world!";
const substring = "world";
if (string.includes(substring)) {
console.log("Substring found!");
} else {
console.log("Substring not found.");
}
3. Using search()
This method searches for a specified substring within a given string and returns the index of the first occurrence.
If the substring is not found, the method returns -1.
The search() method is similar to the indexOf() method but allows the use of regular expressions in the search string.
const string = "Hello world!";
const substring = "world";
if (string.search(substring) !== -1) {
console.log("Substring found!");
} else {
console.log("Substring not found.");
}
These are the top 3 ways to find if a string contains a substring in javascript