title: How can I call a method from a class without instantiating it?
body: <p>If you look at a framework like cocos2d-x, for example:</p>
  <pre><code>cc.Sprite.extend();
  </code></pre>
  <p>Sprite here is a class; how can I call one of its methods without instantiating it with the <code>new</code> keyword?</p>
  <p>For example, if I have this class:</p>
  <pre><code>var superClass = function(){
      
      this.init = function(){
          console.log(&quot;new class constructed !&quot;)
      };
  
  };
  </code></pre>
  <p>To call <code>init</code>, I must do this:</p>
  <pre><code>obj = new superClass();
  obj.init();
  </code></pre>
  <p>But how can I call the function without needing to instantiate the class?</p>