How do I swap substrings within a string?

Question

I am trying to swap all occurrences of a pair of substrings within a given string.

For example, I may want to replace all occurrences of \"coffee\" with \"tea\" and

Answer 1

What about

theString.replace(/(coffee|tea)/g, function($1) {
     return $1 === 'coffee' ? 'tea' : 'coffee';
});

(Personally I think it's a crime to swap coffee and tea, but that's your business)