Regexp Basics - is it all whitespace?.js

/*
Description:
Implement String#whitespace?(str) (Ruby), String.prototype.whitespace(str) (JavaScript), String::whitespace(str) (CoffeeScript), or whitespace(str) (Python), which should return true/True if given object consists exclusively of zero or more whitespace characters, false/False otherwise.
*/
String.prototype.whitespace=function(){
  return /^\s*$/.test(this);
}