why slice() and substr() methods in javascript doesn't work on regular expressions?

Question

my code is:

var st="man myfile=l/p/nm.mp3 yourfile=/o/mj/nnc.mp3 ou p";
var patt=/myfile.[\W|\w]*.mp3\s/;
var s=patt.exec(st);
var s2=s.slice(3,4);
alert(s2);

but slice() gives me nothing and substr() method gives me an error:

Object doesn't support this method

Why?

Answer 1

Fabricio is right. Your variable s is a RegExp object. To access the substring you'll need to do:

var s2 = s[0].substr(3,4);

jsFiddle here.