JS - Object and Property的删除用法

在JS中，Object和Property的删除用法：

 var myObject = {name:'jimmy', age:12, height:123}
 delete myObject["jimmy"];
 delete myObject.age;
 with (myObject) {
    delete height;
 }

 // and an object
 var myObject = new Object();
 delete myObject;

 var myObj2 = {};
 myObj2 = null;