Question

So for instance if I had this string :

"color=green&animal=panda"

Is it possible that I can with regex, return green because it is after color= ?

Answer 1

Since JavaScript does not support look-behinds (unfortunately), you can only do that by including the preceding sub-string. Group green, and refer to the group.

var string = "color=green&animal=panda";
var pattern = /color=(green)/;
var match = pattern.exec(string);
var wantedstring = match[1];

Look-aheads do exist though, so the following can be used to match “green”, but not “greener”:

var pattern = /color=(green)(?=&|$)/;