Prototype - Enumerable grep() Method

This method returns all the elements that match the filter. If an iterator is provided, it is used to produce the returned value for each selected element.

The optional iterator parameter will transform the result set in a manner similar to the map() method.

The optional context parameter is what the iterator function will be bound to. If used, the this keyword inside the iterator will point to the object given by the argument.



Return Value

Returns all the elements for which the iterator returned true.


      <title>Prototype examples</title>
      <script type = "text/javascript" src = "/javascript/prototype.js"></script>
         function showResult() {
            // Get all strings with a repeated letter somewhere
            alert(['hello', 'world', 'is', 'cool'].grep(/(.)\1/).inspect());
            // Returns ['hello', 'cool']

            // Get all numbers ending with 0 or 5
            alert($R(1,30).grep(/[05]$/).inspect() );
            // Returns [5, 10, 15, 20, 25, 30]

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