ts上

如何学习ts？lib.es5.d.ts

• ts改java的设计模式

前端工种：

• 原生、vue2、vue3、react
• node
  • pm2启动cli ts-node
  • gulp编译
• web

新名词：
swc
esbuild
v8-compile-cahche + sparking

数据库连接池

SOLID

// 产品类
class Product {
    deliver () {
        console.log('运输') 
    }
}
class Truck extends Product {
    deliver () {
        console.log('陆运')
    }
}
class Ship extends Product {
    deliver () {
        console.log('海运')
    }
}
// 工厂类
class SimpleFactory {
    create (type) {
        if (type == 'truck') {
            return new Truck();
        } else if (type == 'ship') {
            return new Ship();
        }
    }
}
let t = new SimpleFactory();
t.create('truck').deliver();
let s = new SimpleFactory();
s.create('ship').deliver();
// 陆运
// 海运

控制翻转 IoC

var factory = {};
factory.car = function () {
    console.log('car');
}
factory.plane = function () {
    console.log('plane');
}
factory.manage = function (create) {
    return new factory[create]();
}
let car = factory.manage('car');
let plane = factory.manage('plane');
// car
// plane

系统约束 command键快速跳入

var a = Symbol('Jack');
console.log(a.description);
// Property 'description' does not exist on type 'symbol'
// compiler option to 'es2019' or later
console.log(a.toString());  // Symbol(Jack)
function showWarning(msg: string, mode: typeof a) {
    console.log(mode.description);
}

const textEl = document.querySelector('input');
// console.log(textEl.value); // Object is possibly 'null'
// 常规方式， 先判断， 
if (textEl != null) {
    textEl.addEventListener('click', e => {
        console.log(e.clientX);
    })
    console.log(textEl.value);
}
// 屏蔽null
const text2 = <HTMLInputElement>document.querySelector('input');
console.log(text2.value);