How to replace all occurrences of a string in JavaScript ?

In this article, we will see how to replace all occurrences of a string in JavaScript. We can replace all the occurrences with another string by using replace built-in method. We can also replace it by using various methods.

These are the following methods to replace all occurrences of a string in JavaScript:

• Using string.replace() method
• Using String split() and join() Method
• Using replaceAll() Method
• Using regular expression

Method 1: Using string.replace() method

The string.replace() method is used to replace a part of the given string with another string or a regular expression. The original string will remain unchanged.

Example:

Javascript

// Origin String
const str = 'Welcome GeeksforGeeks, Welcome geeks';

// Replace all occurrence of Welcome with Hello
const newString = str.replace(/Welcome/gi, 'Hello');

// Display the result
console.log(newString);

Output

Hello GeeksforGeeks, Hello geeks

Method 2: Using String split() and join() Method

We can split the strings of text with the JavaScript split method and join strings using the replace characters with the join method. 

Example:

Javascript

// Original String
const str = 'Welcome GeeksforGeeks, Welcome geeks';

// Replace all occurrence of Welcome with Hello
const newString = str.split('Welcome').join('Hello');

// Display the result
console.log(newString);

Output

Hello GeeksforGeeks, Hello geeks

Method 3: Using replaceAll() Method

The replaceAll() method is used to replace all the matches of a string with a specified string or a regular expression. The original string is left unchanged after this operation.

Example:

Javascript

// Original String
const str = 'Welcome GeeksforGeeks, Welcome geeks';

// Replace all occurrences of Welcome with Hello
const newString = str.replaceAll("Welcome", "Hello");

// Display the result
console.log(newString);

Output

Hello GeeksforGeeks, Hello geeks

Method 4: Using regular expression

To replace all occurrences of a string in JavaScript using a regular expression, we can use the regular expression with the global (g) Flag.

Javascript

const str = 'Welcome GeeksforGeeks, Welcome geeks';
const searchString ="Welcome";
const replacementString ="Hello";

let regex = new RegExp(searchString, 'g');
let replacedString = str.replace(regex, replacementString);
console.log(replacedString);

Output

Hello GeeksforGeeks, Hello geeks