Fastest method to replace all instances of a character in a string [duplicate]

Answer 1

You can use the following:

newStr = str.replace(/[^a-z0-9]/gi, '_');

or

newStr = str.replace(/[^a-zA-Z0-9]/g, '_');

This is going to replace all the character that are not letter or numbers to ('_'). Simple change the underscore value for whatever you want to replace it.