title: How to target object method by it name?
body: <p>I don't know how to target a object method by passing it's name to a function as an argument.</p>
  
  <pre><code>var obj = {
      key1: "more",
      target: function()
      {
        return obj.key1 + "DATA"; // cause     key2 : obj.key1 + 'MORE',    is not working (cause this doesn't exist jet)
      },
      func: function(toReplace)
      {
        // I want target obj.target (toREplace function argument tell us what obj key to target) so I can... for example .replace() some of it value, but
        //obj[toReplace] = obj[toReplace].replace('DATA', 'VARIABLES'); // is not working...
        obj.toReplace() = obj.toReplace().replace('DATA', 'VARIABLES'); // is not working either...
      }
  };
  
  console.log(obj.target()); // "moreDATA" - ok
  obj.func('target');
  console.log(obj.target()); // should be "moreVARIABLES"
  </code></pre>