title: How does jquery ready function allow it's first parameter to become jquery object?
body: <p>Today I stumbled upon this:</p>
  <pre><code>jQuery(document).ready(function($$){
      console.log($$);
  });
  </code></pre>
  <p>Apparently, <code>$$</code> is considered as the <code>jQuery</code> object itself. Usually to do such a thing, we need to pass the <code>jQuery</code> variable:</p>
  <pre><code>(function($$){
      console.log($$);
  }(jQuery))
  </code></pre>
  <p>But in case of ready function how does it know <code>$$</code> is the <code>jQuery</code> object? I think jquery defines the  ready function under the hood in a way that passes it's first parameter as <code>jQuery</code>.</p>