JavaScript 对象创建的3种方法

let obj = {}  // 空对象
let obj2 = {a:1, b:2}

let obj3 = {" hel": "wold"}  // 属性名如果有空格，可以用字符串字面量作为属性名

let o = new Object(); // 内置的构造函数

let m = new Math();

let a = new Array();

let d = new Date();

function Person(){  //自定义构造函数

}
let person = new Person()

let o = Object.create({x:1, y:2});
console.log(o.x+o.y) //3

Object.create(null)

let foo  = {x:1, y:2}
let bar  = {z:3}

let zoo = {...foo, ...bar}

console.log(zoo) // {x:1, y:2, z:3}

let foo  = {x:1, y:2}
let bar  = {z:3}

let zoo = {}

let obj = Object.assign(zoo, foo, bar)

console.log(zoo)  // {x:1, y:2, z:3}

console.log(obj===zoo) // true  

let x=1, y =2;
let o = {x:x, y:y}

console.log(o) // {x:1, y:2}

let o2 = {x, y}

console.log(o2) // {x:1, y:2}

let point={
    x:1,
    y:2,

    area: function(){
        return this.x*this.y
    }
}

console.log(point.area()) //2

let point2={
    x:1,
    y:2,

    area(){
        return this.x*this.y
    }
}

console.log(point2.area()) //2