title: javascript function with an argument calling without argument
body: <p>can somebody tell me, how it works
  for example</p>
  
  <pre><code>function animate(t) {   
      sun.rotation.y = t/1000;
      renderer.clear();
      camera.lookAt(sun.position);
      renderer.render(scene, camera);        
      window.requestAnimationFrame(animate, renderer.domElement);
  };
  animate(new Date().getTime());
  </code></pre>
  
  <p>as you see, animate() function has the argument "t". And we call this function with it. But inside the animate() func requestAnimationFrame  called it without "t" and program works perfect..im confused</p>