var test = {
_Name : null,
_Age : 0,

//_Name的讀寫
set name(name) {this._Name = name;},
get name() {return this._Name;},
//_Age的讀寫
set age(age) {this._Age = age;},
get age() {return this._Age;}
}

alert(test.name + " " + test.age);//bull 0
test.name = 'lucy';
test.age = 20;
alert(test.name + " " + test.age);//lucy 20