title: how is that the jquery function can start with '$'?
body: <p>if you declare a function in javascript, you can't use the '$' character in the name, so how is that jquery is able to do so?  For example:</p>
  
  <pre><code>function myFunction() {
      $("#h01").html("Hello jQuery")
  }
  $(document).ready(myFunction);
  </code></pre>
  
  <p>but if i declare a function as so:</p>
  
  <pre><code>function $(a){
  // do something
  }
  </code></pre>
  
  <p>javascript shows an error?  </p>