五、ES6之对象

一、对象和属性和方法

JavaScript中对象：

var person={name:"Jack",age:20};

或：

var name = "jack";
var age = 20;
var person = {name:name,age:age};
console.log(person.age); //20

ES6中的简洁表示：

let [name,age]=["jack",20];
let person = {name,age}; //等同person = {name: name,age: age}
console.log(person.age); //20

---

JavaScript中对象方法：

var person = {
    SayHi:function()
    {
    	console.log("hi");
    }
}
person.SayHi();  //hi

ES6中简洁表示：

let person = {
    SayHi()
    {
    	console.log("hi");
    }
}
person.SayHi();

---

ES6允许用表达式作为属性名，但是一定要将表达式放在方括号内：

var person = {["na"+"me"]:"jack",["a"+"ge"]:20};
console.log(person.age);

或

let str = "Hi";
let person = {
    ["Say"+str](){
    	console.log("hi");
    }
}
person.SayHi();

注意点：属性的简洁表示法和属性名表达式不能同时使用，否则会报错：

let [name,age]=["jack",20];
let person = {["na"+"me"],["a"+"ge"]}; //报错

二、对象的扩展运算符...

取出参数对象所有可遍历属性然后拷贝到当前对象：

let stu1 = {name:"Jack",age:20,sex:"男"};
let stu2 = {...stu1};
console.log(stu2); //{name: "Jack", age: 20,sex:"男"}

合并两个对象：

let stu1BasicInfo = {name:"Jack",age:20,sex:"男"};
let stu1DetailInfo = {phone:"13524521457",mail:"ldh@163.com"};
let stu = {...stu1BasicInfo,...stu1DetailInfo};
console.log(stu);
//{name:"Jack",age:20,sex:"男",phone:"13524521457",mail:"ldh@163.com"}

拷贝对象时支持添加属性：

let stu1 = {name:"Jack",age:20,sex:"男"};
let stu2 = {...stu1,phone:"13554785452"};
console.log(stu2); //{name:"Jack",age:20,sex:"男",phone:"13554785452"}

添加的属性在拓展运算符后面，取添加的属性：

let stu1 = {name:"Jack",age:20,sex:"男"};
let stu2 = {...stu1,name:"rose",phone:"13554785452"};
console.log(stu2);
//{name:"rose",age:20,sex:"男",phone:"13554785452"}

添加的属性在拓展运算度前面，取扩展运算符内容：

let stu1 = {name:"Jack",age:20,sex:"男"};
let stu2 = {name:"rose",phone:"13554785452",...stu1};
console.log(stu2);
//{name:"Jack",phone:"13554785452"，age:20,sex:"男"}