Question

I’m actually trying to delete every space in a small function statement excepted if the word “function” or “return” comes before it. This is what I tried but to no avail:

function hi() {
    return "Hello";
}
hi.toString().replace(/\b\s+?=(return|function)/g, '');

Answer 1

There is no lookbehind in javascript regex, but this should do the trick:

hi.toString().replace(/(return|function)?\s/g, function(match) {
    if (match.length > 1) return match;
    else return '';
});

This matches single spaces, eventually preceeded by function or return.

If the match is a single character, we replace it by an empty string. Else, we do not replace it.

Try it here: http://jsfiddle.net/ebY5w/2/