一卸伞、類
class ClassA{
constructor(o){
Object.assign(this, o);
}
foo(){
console.log(this);
}
static bar(){
console.log("我是一個(gè)靜態(tài)方法衰齐，不能通過實(shí)例化對(duì)象調(diào)用，只能通過類本身調(diào)用");
}
}
let a = new ClassA({
a : 1,
b : 2,
c : 3
});
ClassA.bar();
a.foo();
二萝勤、類的繼承
class ClassA{
constructor(o){
if(new.target !== ClassA){
console.log("通過子類調(diào)用的");
}else{
console.log("被單獨(dú)調(diào)用的");
}
Object.assign(this, o);
}
foo(){
console.log("我是classA的foo方法");
}
bar(){
console.log("我是classA的方法");
console.log(this);
}
}
class ClassB extends ClassA{
constructor(o){
super(o);
}
foo(){
super.foo();
console.log("我是classB的foo方法");
}
}
let b = new ClassB({a:1});
//ClassB.prototype -> b.__proto__
//b.foo();
三露筒、模塊與import語法
import() 返回一個(gè)promise對(duì)象
需要export暴露
let dir = "./export1.js";
if(true){
import(dir)
.then((module)=>{
let {a, foo, ClassA} = module;
foo();
console.log(a, foo, ClassA);
console.log(module.default);
})
}
(async function(){
let {c, b, foo} = await import(dir);
console.log(c, b, foo);
})()
let a = 1;
let b = 2;
function foo(){
console.log("foo");
}
//as取別名
export {a as c, b, foo}
export let a = 1;
export function foo(){
console.log("foo");
}
export class ClassA{
constructor(){}
}
export default class ClassA{
constructor(){}
}
import第二種用法，瀏覽器可能不支持敌卓，微信小程序已經(jīng)支持
//代碼編譯階段執(zhí)行
import {b, foo} from "../../export/export1.js";
console.log(b, foo);
import ClassB from "../../export/export2.js";
new ClassB();
import * as modules from "../../export/export1.js";
console.log(modules);
let a = 1;
let b = 2;
let foo = function(){
console.log("foo");
}
export {a, b, foo};
export default class ClassA{
constructor(){
console.log(this);
}
}
