JavaScript: jsExtend

jsExtend.js

var isFunction = function(target){
  var getType = {};
  return !!target &&
          (getType.toString.call(target) === '[object Function]' ||
          typeof target === 'function');
};

var objectExtend = function(where) {
  Array.prototype.slice.call(arguments, 1).forEach(function(source) {
    var key;
    for (key in source) {
      if (source.hasOwnProperty(key)) {
        where[key] = source[key];
      }
    }
  });
  return where;
};