<?php class JavaScriptPacker { public function foo() { $encode10 = $this->_getJSFunction('_encode10'); var_dump($encode10); $encode36 = $this->_getJSFunction('_encode36'); var_dump($encode36); } private function _getJSFunction($aName) { if (defined('self::JSFUNCTION' . $aName)) { return constant('self::JSFUNCTION' . $aName); } else { return ''; } } const JSFUNCTION_encode10 = 'function($charCode) { return $charCode; } '; } $obj = new JavaScriptPacker(); $obj->foo();