JavaScript - replace last n characters in string

In this article, we're going to have a look at how to replace the last n characters from string in JavaScript.

1. String slice() method example

This approach allows getting substring by using negative indexes. So by using 0 and -n indexes as the range we get <0, text.length - n> text range. Then, we add the replacement at the end of the result string to replace the missing two characters.

// ONLINE-RUNNER:browser;

let text = 'ABCD';
let n = 3;
let replacement = 'xyz';
let result = text.slice(0, -n) + replacement;

console.log(result); // Axyz

2. String substring() method example

This is an alternative approach to slice method based solution. We remove the last n characters to add the replacement at the end of the result string to replace the missing n characters.

// ONLINE-RUNNER:browser;

let text = 'ABCD';
let n = 3;
let replacement = 'xyz';
let result = text.substring(0, text.length - n) + replacement;

console.log(result); // Axyz

See also

1. JavaScript - replace last character in string

2. JavaScript - replace last 2 characters in string

3. JavaScript - replace last 3 characters in string

4. JavaScript - replace last 4 characters in string