工厂模式

factory_pattern.js

let carFactory = (function (name) {
  function Benz() {
    this.name = 'benz';
  }
  function BMW() {
    this.name = 'bmw';
  }
  return function(name) {
    switch (name) {
      case 'benz':
        return new Benz();
      case 'bmw':
        return new BMW();
      default:
        console.warn('car factory required an car name!');
        break;
    }
  }
})();

let bmw = carFactory('bmw');
console.log(bmw);
let lincoln = carFactory('lincoln');
console.log(lincoln);