Testing for a Function's Existence : function_exists « Functions « PHP

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PHP » Functions » function_exists

Testing for a Function's Existence

 

<html>

<body>

<div>

<?php

    function tagWrap( $tag, $txt, $func="" ) {

      if ( function_exists( $func ) )

        $txt = $func( $txt );

      return "<$tag>$txt</$tag>\n";

    }

    

    function subscript( $txt ) {

      return "<sub>$txt</sub>";

    }

    

    print tagWrap('b', 'bold');

    

    print tagWrap('i', 'i', "subscript");

   

?>

</div>

</body>

</html>

Related examples in the same category

bool function_exists ( string function_name ) returns true if that function is available for use.

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