title: (this) after function declaration
body: <p>Can somebody explain me what <code>(this)</code> means at the end of the following code:</p>
  
  <pre><code>var a=(function(_this){
   return function() {
    //do something
    return smth;
   };
  })(this);
  </code></pre>
  
  <p>What is the sense of such coding?</p>
  
  <hr>
  
  <p>Going forward, what does the following code do, when placed in .js file and invoked by html  tag?</p>
  
  <pre><code>(function() {
   Emitter=(function(){
    function Emitter() {}
    ...
    return Emitter;
   })();
   A=(function(_super){...})(Emitter);
  }).call(this);
  </code></pre>
  
  <p>how to instantiate object A from outside the js file? </p>