JavaScript String replaceAll()

replaceAll() Syntax

The syntax of replaceAll() is:

str.replaceAll(pattern, replacement)

Here, str is a string.

replaceAll() Parameter

The replaceAll() method takes in:

• pattern - either a substring or a regex that is to be replaced
• replacement - the pattern is replaced with this replacement (can be either a string or a function)

replaceAll() Return Value

• The replaceAll() method returns a new string, with all matches of a pattern replaced by a replacement.

Note: A RegExp without the global ("g") flag will throw a TypeError.

Example 1: Using replaceAll()

Output

JavaScript is awesome. JavaScript is fun
JavaScript is awesome. JavaScript is fun.

Replace Without Considering Uppercase/Lowercase

The replaceAll() method is case sensitive. To perform the case-insensitive replacement, you need to use a regex with a i switch (case-insensitive search).

Example 2: Case-Insensitive Replacement

Output

JS JS

Example 3: Passing Function as a Replacement

You can also pass a function (instead of a string) as the second parameter to the replaceAll() method.

Output

4.3518

You may get different output when you run this program. It's because the first digit in text is replaced with a random digit between 0 and 9.

Recommended Reading: JavaScript String replace()