# 1.2.3.2.物件與物件實體

* 當JavaScript engine 看到大括號時, 就會假設在創造一個物件
  *   物件實體 (object literals)

      ```
      //物件實體語法
      var person = {
        firstname:  'Tony', 
        lastName: 'Alicea',
        address: {
            street: "111 main st.";
            city = "new york";
        }
      };

      function greet(person){
        console.log('Hi' + person.firstname);
      }

      greet(Tony);
      greet({firstname: 'Mary', lastname: 'Doe'});
      ```
* 因為JavaScript code並不是真正被處理, 而是經過JavaScript engine處理過, 因此可以有多種寫法
