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# Prototype Enumerable detect() Method

This method finds the first element for which the iterator returns true. This method is aliased as find() method.

## Syntax:

    Iterator.detect([context]);

## Return Value :

- Returns first element for which the iterator returns true otherwise undefined.

## Example:

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

    <script>

    function isPrime(n) {
      if (2 > n) return false;
      if (0 == n % 2) return (2 == n);
      for (var index = 3; n / index > index; index += 2)
        if (0 == n % index) return false;
      return true;
    } // isPrime

    function showResult(){
      alert($R(10,15).detect(isPrime) );
    }

    </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.

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