phpjs/functions/var/is_resource.js

php.js offers community built php functions in javascript

function is_resource(handle) {
  // From: http://phpjs.org/functions
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // +   improved by: Luis Salazar (http://www.freaky-media.com/)
  // *     example 1: is_resource('a');
  // *     returns 1: false
  var getFuncName = function(fn) {
    var name = (/\W*function\s+([\w\$]+)\s*\(/).exec(fn);
    if (!name) {
      return '(Anonymous)';
    }
    return name[1];
  };
  return !(!handle || typeof handle !== 'object' || !handle.constructor || getFuncName(handle.constructor) !== 'PHPJS_Resource');
}