Extract a substring from a string between two substrings.

String.extract.func.js

String.prototype.extract = function(start, finish){
  var s = this.indexOf(start);
  if(s == -1) return "";
  var e = this.indexOf(finish, s + start.length);
  if(e == -1) return "";
  return this.substring(s + start.length, e);
}

String.extract.func.min.js

String.prototype.extract=function(t,n){var r=this.indexOf(t);if(-1==r)return"";var i=this.indexOf(n,r+t.length);return-1==i?"":this.substring(r+t.length,i)};