摘要：模板語言塊級(jí)作用域定義的是常量聲明的變量，內(nèi)存地址不可以改變，但是空間的值可以改報(bào)錯(cuò)常量不能改變解構(gòu)賦值傳統(tǒng)的寫法是展開運(yùn)算符數(shù)組對(duì)象做一些異步操作異步任務(wù)執(zhí)行完成數(shù)據(jù)做一些異步操作異步任務(wù)執(zhí)行完成數(shù)據(jù)做一些異步操作異步任務(wù)執(zhí)行完成數(shù)據(jù)如有

var str  = `
    var a = 1;
    console.log(a)
`;

let userName = "Dean";
console.log( ` I"m ${userName } ` ) ; //  I"m Dean

塊級(jí)作用域：

{
    let a = 1;
    var b = 2;
}
console.log(a)  // a is not defined
console.log(b)  // 2

const定義的是常量
（const聲明的變量，內(nèi)存地址不可以改變，但是空間的值可以改）

let a = 1;
a = 2;
const b = 2;
b = 3;  // 報(bào)錯(cuò)：  Assignment to constant variable （常量不能改變）

const {
    resName,
    resPosition,
    parkAreaNum,
    parkStationNum,
    resDesImg
} = resProduct.data;

Object.assign(vm, {
    resName,
    resPosition,
    parkAreaNum,
    parkStationNum,
    resDesImg
});

傳統(tǒng)的寫法是： vm.resName = resProduct.data.resName

function sum(...m){
      let total = 0;
      for(var i of m) {
        total += i;
      }
      console.log(`total: ${total}`)
    }
sum(4,5,6,9);

數(shù)組

const color = ["red", "yellow"];
const colorful = [...color, "green", "pink"];
console.log(colorful); //[red, yellow, green, pink]

對(duì)象

const alp = { fist: "a", second: "b" };
const alphabets = { ...alp, third: "c" };
console.log(alphabets); //{ "fist": "a", "second": "b", "third": "c"

function runAsync1() {
    var p = new Promise(function(resolve, reject) {
        //做一些異步操作
        setTimeout(function() {
            console.log("異步任務(wù)1執(zhí)行完成");
            resolve("數(shù)據(jù)1");
        }, 1000);
    });
    return p;
}

function runAsync2() {
    var p = new Promise(function(resolve, reject) {
        //做一些異步操作
        setTimeout(function() {
            console.log("異步任務(wù)2執(zhí)行完成");
            resolve("數(shù)據(jù)2");
        }, 2000);
    });
    return p;
}

function runAsync3() {
    var p = new Promise(function(resolve, reject) {
        //做一些異步操作
        setTimeout(function() {
            console.log("異步任務(wù)3執(zhí)行完成");
            resolve("數(shù)據(jù)3");
        }, 2000);
    });
    return p;
}

runAsync1()
  .then(function(data) {
    console.log(data);
    return runAsync2();
  })
  .then(function(data) {
    console.log(data);
    return runAsync3();
  })
  .then(function(data) {
    console.log(data);
  });

import util from "../../js/util.js";
export default {
    name: "home",
    data () {},
    methods: {}
}

（如有不足之處，請(qǐng)多指教）