对象成员简写

• 现在声明一个对象
• 对象里面有name，age，gender，score属性
• 希望这些属性的值是上面对应变量的值
  测试代码

//es5
/*
var obj = {
    name:name,
    age:age,
    gender:gender,
    score:score,
    sayHi:function(){
        console.log('你好');
    }
}

console.log(obj)
obj.sayHi()
*/

//es6
var obj = {
    name,
    age,
    gender,
    score,
    fenshu:score,
    sayHi(){
        console.log('你好')
    }
}

console.log(obj)
obj.sayHi()

对象解构赋值

• 取对象中属性的值，赋值给变量
  测试代码

//声明一个变量
let obj = {
    name:'111',
    age:29,
    gender:'男',
    score:100
}

/*
es5
let name1 = obj.name;
let age1 = obj.age;
let gender1 = obj.gender;
let score1 = obj.score;
console.log(name1,age1,gender1,score1)
*/

/*
es6
a.
let {name:name1,age:age1,gender:gender1,score:score1} = obj;
console.log(name1,age1,gender1,score1)
*/

/*
b.
let {name:name.age:age,gender:gender,score:score}
console.log(name,age,gender,score)
*/

/*
c.如果声明的变量名和对象属性名一致，可以简写
let {name,age,gender,score};
console.log(name,age,gender,score)
*/

/*
d.obj中没有属性，输出为undefined
let {name,age,gender,fenshu}
console.log(name,age,gender,fenshu)
*/

/*
e.fenshu取score属性的值
let {name,age,gender,score:fenshu}
console.log(name,age,gender,fenshu)
*/

/*
f.使变量有默认值
let {name,age,gender,fenshu=120}
console.log(name,age,gender,fenshu)
*/

展开运算符/对象展开

测试代码

//声明一个对象
let fn = {
    name:'111',
    age:29,
    sayHi(){
        console.log('测试')
    }
}

//声明一个对象
let fun = {
    name1:'222',
    age1:20
}

//声明一个对象
let linge = {
    //name2:'333',
    //age2:29,
    //sayHi(){
    //    console.log('测试')
    //},
    //shill:'444',
    //song:'333'

    //展开语法
    ...fn,
    ...fun,
    gender:'男',
    age:49
}
console.log(linge)