How to Replace All Occurrences of a String in JavaScript

In this tutorial, we are going to learn about how to replace the all occurrences of a string in JavaScript with the help of a replace() method and split() method.

Using the replace method

The replace() method accepts the two arguments, the first one is regex and the second one is replacement value.

Example:

const str = "hello fun good morning fun morning fun etc";
                 //str.replace(regex, replacementvalue);
const replaced = str.replace(/fun/g,'');

console.log(replaced);
//Ouput--> hello  good morning  morning  etc

In the above example, we are replacing the fun from the following string with an empty value using replace() method.

• The regex /fun/g we used a g flag so that it can replace the fun value at a global level instead of stopped replacing after the first occurrence.

If you want to replace case insensitive words in your string you can use i flag.

const str = "hello fun good morning Fun morning fun etc Fun";
const replaced = str.replace(/fun/gi,'');

console.log(replaced); //hello  good morning  morning  etc

This i flag will replace both fun and Fun in a given string.

Using split and join methods

Let’s see, how can we use split() and join() methods to replace all occurrences of a string.

The split() method splits the string where it finds the pattern, and return the array of strings.

const str = "hello fun good morning Fun morning fun etc Fun";

const split = str.split('fun');

//split--> ["hello ", " good morning Fun morning ", " etc Fun"]

Now we need to combine the array of strings into a single string using the join() method.

const final = split.join('');
//"hello  good morning Fun morning  etc Fun"

We can also add the replacement value inside join() method instead of empty quotes.

const str = "hello fun good morning Fun morning fun etc Fun";

const final = str.split('fun').join('king');
console.log(final);
//"hello king good morning Fun morning king etc Fun"