ES6学习记录 part1

let [a,b,c] = [1,2,3];//依次为a,b,c赋值为1,2,3

let [one,,three] = [1,2,3]//one =1;three =3

let [top1, ...bottom] = [1,2,3,4];//top1 = 1 ; bottom = [2,3,4]

let [x, y, ...z] = ['a']; //x = a; y = undefined; z = [];

let [first,seconed] = [1];//解构失败，都为undefined

let [defaultValue = 'yes'] = []; //defaultValue = yes;

let [defaultValue2 = 'yes'] = [null]; defaultValue2 = null;//当一个数组成员严格等于undefined，默认值才会生效

function f() {

  console.log('aaa');

 }

 let [x1 = f()] = [1];

// 在这种情况下f()不会执行,只有当需要采取默认值的时候才会执行f()；

//数组的元素是按次序排列的，变量的取值由它的位置决定；而对象的属性没有次序，变量必须与属性同名，才能取到正确的值。解构失败值为undefined



let {aaa,bbb,ccc} = {aaa:'a',ccc:'c',bbb:'b'};



const KXS = {

  name: 'azirkxs',

  age: 21,

  play: function(){

​    console.log('happy game');

  }

}



let {name,age,play} = KXS; //此处的变量名必须与对象中的属性名一致

console.log(name);

console.log(age);

play();

let azir = '阿兹尔';

let info = `${azir}是恕瑞玛的皇帝`;

console.log(info);

//在学习框架阅读框架源码的时候可能会出现这种降低可读性的写法！

let zed = '劫';

const R = function(){

  console.log("劫使用了大招");

}



let game = {

  zed, // zed = zed

  R,//  R = R;

  die(){ // die =function()

    console.log("劫死了");

  }

}

console.log(game.zed,game.R);

game.die();

window.name = 'azirkxs';

const nickname = {

  name: '勤勉的阿库希斯教徒'

}



let getName0 = function(){

  console.log(this.name);

}



let getName1 =() =>{

  console.log(this.name);

}

getName0.call(nickname);

getName1.call(nickname);

let add = a => a+a;

//ES6允许为形参赋默认值

function test(a,b,c=10){

  return a + b +c;

}

console.log(test(1,2));//13