How to replace a character in a string using JavaScript

You can use the replace() method to replace the occurrence of a character inside a string in JavaScript.

Here is an example that replaces a character in a string with another character using the replace() method:

const str = 'Hello World!'

const updated = str.replace('l', '!')

console.log(updated)
// He!lo World!

By default, the replace() will only replace the first occurrence of the specified character.

To replace all occurrences of a specified character, you must use a regular expression with the global modifier (g):

const str = 'Hello World!'

const updated = str.replace(/l/g, '!')

console.log(updated)
// He!!o Wor!d!

For a global case-insensitive replacement, you can combine the global modifier (g) with the ignore case modifier (i):

const str = 'HeLLo World!'

const updated = str.replace(/l/gi, '!')

console.log(updated)
// He!!o Wor!d!

Alternatively, you could use the replaceAll() method to replace all occurrences of a character inside a string:

const str = 'HelLo World!'

const updated = str.replaceAll(/l/gi, '!')

console.log(updated)
// He!!o Wor!d!

The replaceAll() method was introduced in ES2021. It replaces all occurrences of the search string with the replacement text and returns a new string.

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