How to create a string "replace all" function?

Question

Every article or question I've seen pretty much says, just use:

str.replace(/yourstring/g, 'whatever');

But I want to use a variable in place of "yourstring". Then people say, just use new RegExp(yourvar, 'g'). The problem with that is that yourvar may contain special characters, and I don't want it to be treated like a regex.

So how do we do this properly?

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Example input:

'a.b.'.replaceAll('.','x')

Desired output:

'axbx'

• David Thomas: You want to not treat regex like regex? Can you define the types of input you'd like to provide? Will you want regex-functionality, or is it just a string of literal characters, "ABc34*\d/4h" you want to work with/replace?
• mpen: @DavidThomas: Any input. All I want is a simple function that replaces all instances of "x" with "y", not just the first one, as string.replace does.
• david: 'a.b.c'.split('.').join('x')

Answer 1

You can split and join.

var str = "this is a string this is a string this is a string";
str = str.split('this').join('that');
str; // "that is a string that is a string that is a string";

• mpen: This solution seems to be significantly faster, so you get the check. Wouldn't have thought of doing this; thanks.

Answer 2

From http://cwestblog.com/2011/07/25/javascript-string-prototype-replaceall/

String.prototype.replaceAll = function(target, replacement) {
 return this.split(target).join(replacement);
};

Answer 3

you can escape your yourvar variable using the following method:

function escapeRegExp(text) {
 return text.replace(/[-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&");
}

• mpen: I think you went a little excessive on the backslashes. When inside a character set, you don't need to escape much. Nevertheless, this is a viable solution. +1

Answer 4

XRegExp provides a function for escaping regular expression characters in strings:

var input = "$yourstring!";
var pattern = new RegExp(XRegExp.escape(input), "g");
console.log("This is $yourstring!".replace(pattern, "whatever"));
// logs "This is whatever"

• mpen: I don't really want the whole library, so I dug through the source: nativ.replace.call(str, /[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&"); Library does look neat though.

Answer 5

Solution 1

RegExp.escape = function(text) {
 return text.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&");
}
String.prototype.replaceAll = function(search, replace) {
 return this.replace(new RegExp(RegExp.escape(search),'g'), replace);
};

Solution 2

'a.b.c.'.split('.').join('x');

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