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# Prototype $$() Method

The $$() method parses one or more CSS filtering expressions, analogous to the ones used to define CSS rules, and returns the elements that match these filters.

## Syntax:

    $$(cssRule...);

## Return Value:

- An array of HTML elements.

## Example:

Here is old way of writing Javascript statement to get all the node of DOM with name div.

    nodes = document.getElementsByTagName('div');

Using $$(), we can shorten it up as follows:

    nodes = $$('div');

Following is same as $('contents'), only it returns an array anyway.

    $$('#contents');

## Example:

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

      function test(){
           allNodes = $$("div");
           for(i = 0; i < allNodes.length; i++) {
             alert(allNodes[i].innerHTML);
           }
       }
       </script>
    </head>

    <body>
       <div id="firstDiv" name="div">
          <p>This is first paragraph</p>
       </div>

       <div id="secondDiv" name="div">
          <p>This is another paragraph</p>
       </div>

       <input type="button" value="Test $()" onclick="test();"/>

    </body>
    </html>

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

## More Examples:

Following returns all links inside the element of ID "contents" with a rel attribute

    $$('#contents a[rel]');

Following returns all links with a href attribute of value "#" (eyeew!)

    $$('a[href="#"]');

Following returns all links within the elements of ID "navbar" or "sidebar"

    $$('#navbar a', '#sidebar a');

Following returns all links, excluding those whose rel attribute contains the word "nofollow"

    $$('a:not([rel~=nofollow])');

Following returns all even rows within all table bodies.

    $$('table tbody > tr:nth-child(even)');

Following returns all DIVs without content (i.e., whitespace-only)

    $$('div:empty');

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