Replace Multiple Instances of Pattern in JavaScript

How to replace multiple instances of a pattern in JavaScript with a regular expression.

If you want to replace a pattern multiple times with the JavaScript replace method, you have to use a regular expression with the global flag.

Replacing the first found instance is achieved with the following:

"this is a string".replace(" ", "-");


"this-is a string"

When calling the replace method with a string as the first argument, it will only replace the first instance with the replace value (in this case "-").

Replacing all found instances is achieved with a regular expression and global flag:

"this is a string".replace(/ /g, "-");



When the replace method with a regular expression and the global flag, it will replace all instances with the replace value.

Share on Twitter