// function factory(type){ // switch(type){ // case 'D': // return new Date(); // case 'O': // return {}; // default: // return null // } // } // console.log(factory('D')) // console.log(factory('O')) function A(){} function I(){} function Factory(){} Factory.prototype.create = function(type){ switch(type) { case 'A': return new A; case 'I': return new I; } } var factory = new Factory() console.log(factory.create('A')) console.log(factory.create('I'))