Prototype clear() Method

Syntax:

array.clear()  ;

Return Value:

Returns an empty array.

Example:

<html>
<head>
<title>Prototype examples</title>
<script type="text/javascript" 
   src="/javascript/prototype.js">
</script>
<script>

function showResult(){

   var guys = ['Sam', 'Justin', 'Andrew', 'Dan'];
   alert("Before using clear" );
   guys.each(function(item) {
      alert(item );
   });
   guys.clear();
   alert("After using clear" );
   guys.each(function(item) {
      alert(item );
   });
 
}

</script>
</head>

<body>

  <p>Click the button to see the result.</p>
  <br />
  <br />
  <input type="button" value="Result" onclick="showResult();"/>

</body>
</html>

To understand it in better way you can Try it yourself.