ts随笔
npm install react-router-dom --save //路由
npm install axios --save //axios
npx create-react-app my-app --template typescript --use-npm
npx :避免安装模块 ，调用 项目中模块
配置
quote TypeScript › Preferences: Quote Style--single
tab ：
Prettier - Code formatter 插件：
save ：
安装。
npm install typescript@3.6.4 -g
tsc 名字.ts //转为js
npm install -g ts-node
ts-node demo.ts // 运行
在浏览器运行
npm init -y
tsc-init
创建src目录- page.ts
编辑tsconfig.json
其中rootDir 编译的文件目录 ‘./src’
出口outDir ‘./dist’
最外层创建index.html
<body>
<script src='./dist/page.js'></script>
</body>
tsc -w 监听模式
ts基本语法
类型
const count: number = 2020;
let temp: number | string = 123;
temp = "asd";
//对象类型
interface Point {
x: number;
y: number;
}
const point: Point = {
x: 3,
y: 4,
};
point.x
const teacher：{
name:string;
age:number
}={
name:'Dell',
age:18
};
const numbers:number[]=[1,2,3] //正确
const numbers:number[]=[‘123’,2,3] //错误
class Person {}
const dell:Person =new Person();
const getTotal: () => number = () => {
return 1523;
};
类型推断
function getTotal(firstnumber: number, secondnumber: number) {
return firstnumber + secondnumber;
}
getTotal(123, 546);
函数相关类型
// 函数相关类型
// function hellow() {}
// const hellow = function () {};
function getTotal(firstnumber: number, secondnumber: number): number {
return firstnumber + secondnumber;
}
getTotal(123, 546);
function satHello(): void {
// void返回空 不允许有返回值
console.log("hello");
}
function errorEmitter(): never {
//无限执行
// throw new Error();
while (true) {}
}
// 解构赋值类型写法
function add({ first, second }: { first: number; second: number }): number {
return first + second;
}
add({ first: 1, second: 2 });
//函数声明
function App （ x:number,y:string,z:number=10）{}
数组和元组
// 数组和元组
const arr: (number | string | {})[] = [1, 2, 3, "sad", { name: "223" }];
type User = { name: string; age: number };
const objectArr: User[] = [
{
name: "dell",
age: 28,
},
];
class Teacher {
name: string;
age: number;
}
const objteacther: Teacher[] = [
new Teacher(),
{
name: "Lily",
age: 20,
},
];
// 元组 约束内容
const teacherInfo: [string, string, number] = ["Dell", "male", 20];
接口interface
type name = string; //类型别名直接可以代表一个类型
interface Person {
name: string; // readonly 只读无法修改
age?: number; //可有可无
[propName: string]: any;
say(): string;
} //接口 代表函数对象
interface Teacher extends Person {
//继承
teach(): string;
}
// ---------------------
const getPersonName = (person: Person): void => {
console.log(person.name);
};
const setPesonName = (person: Teacher, name: string): void => {
person.name = name;
};
const person = {
name: "dell",
sex: "male",
say() {
return "say";
},
teach() {
return "sas";
},
};
getPersonName(person);
// getPersonName({
// name: "dell",
// sex: "male",
// });
setPesonName(person, "lee");
// -------------
class UserA implements Person {
//类去应用接口
name = "dell";
say() {
return "hellow";
}
}
// -----------------------
interface SayHi {
//函数类型
(word: string): string;
}
const say: SayHi = (word: string) => {
return "word";
};
类的继承
(function () {
class Person {
name = "dell";
getName() {
return this.name;
}
}
class Teacher extends Person {
getTeacherName() {
return "teacher";
}
getName() {
//重写 在子类中
// return "newdell";
return super.getName() + "newdell";
//super 调用父类方法
}
}
const person = new Person();
console.log(person.getName());
const teacher = new Teacher();
console.log(teacher.getName());
console.log(teacher.getTeacherName());
})();
public-private-protected
(function () {
// public 允许我在类内外被调用
//private 允许在类内被使用
// protected 允许在类内及继承的子类中使用
(function () {
class Person {
public name: string;
public sayHi() {
console.log("hi");
}
private sayABC() {
this.name;
}
}
class Teacher extends Person {
sayBye() {
this.name;
}
}
const person = new Person();
person.name = "dell";
console.log(person.name);
person.sayHi();
});
// -----------------------------------
// class Person {
// // public name: string;
// constructor(public name: string) {
// // this.name = name;
// }
// }
// const person = new Person("dell");
// console.log(person.name);
class Person {
constructor(public name: string) {}
}
class Teacher extends Person {
constructor(public age: number) {
super("dell"); //调用父类
}
}
const teacher = new Teacher(28);
console.log(teacher.name);
})();
setter -getter /单列
(function () {
class Person {
constructor(private _name: string) {}
get name() {
//设置
return this._name + "lee";
}
set name(name: string) {
//改
const realName = name.split(" ")[0];
this._name = realName;
}
}
const person = new Person("dell");
console.log(person.name);
person.name = "delsl lee";
console.log(person.name);
})();
//单例模式
class Demo {
private static instance: Demo;
private constructor(public name: string) {}
static getInstance() {
if (!this.instance) {
this.instance = new Demo("dell lee");
}
return this.instance;
} //static 挂载到demo 而不是实例
}
const demo1 = Demo.getInstance();
const demo2 = Demo.getInstance();
抽象类 -接口interface 继承
(function () {
// class Person {
// public readonly name: string; //readonly 只读
// constructor(name: string) {}
// }
// const person = new Person("dell");
// // person.name = "hello";
// console.log(person.name);
// -------------------------------------
//抽象类
abstract class Geom {
//抽象类只能被继承
width: number;
getType() {
return "Gemo";
}
abstract getArea(): number;
}
class Circle extends Geom {
getArea() {
return 123;
}
}
// ----------------------
interface Person {
name: string;
}
interface Teacher extends Person {
teachingAge: number;
}
interface Student extends Person {
age: number;
}
interface Driver {
name: string;
age: number;
}
const teacher = {
name: "dell",
teachingAge: 3,
};
const student = {
name: "lee",
age: 18,
};
const getUserInfo = (user: Person) => {
console.log(user.name);
};
getUserInfo(teacher);
})();
语法进阶
类型断言/类型保护
(function () {
interface Bird {
fly: boolean;
sing: () => {};
}
interface Dog {
fly: boolean;
bark: () => {};
}
//类型断言
function trainAnial(animal: Bird | Dog) {
//联合类型
if (animal.fly) {
(animal as Bird).sing();
} else {
(animal as Dog).bark();
}
}
//in 语法
function trainAnialSecond(animal: Bird | Dog) {
if ("sing" in animal) {
animal.sing();
} else {
animal.bark();
}
}
function add(first: string | number, second: string | number) {
if (typeof first === "string" || typeof second === "string") {
return `${first}${second}`;
}
return first + second;
}
class NumberObj {
count: number; //instanceof
}
});
枚举
//枚举
enum Status {
OFFLINE, //默认为0
ONLINE,
DELETED,
}
// enum Status {
// OFFLINE=2,
// ONLINE, //3
// DELETED, //4
// }
console.log(Status.DELETED);
console.log(Status[0]); //ODDLine
泛型基础
// function join(first:string|number,second:string|number) {
// return `${first}${second}`
// }
// join(1,1)
// 泛型
function join<ABC>(first: ABC, second: ABC) {
return `${first}${second}`;
}
join<string>("1", "2"); //<number>
function map<ABC>(params: ABC[]) {
return params;
}
map<string>(["2", "ss"]);
function joinA<ABC, DEF>(first: ABC, second: DEF) {
return `${first}${second}`;
}
joinA<string, number>("1", 2); //<number>
// 类中使用泛型
interface Item {
name: string;
}
class DataManager<asd extends Item> {
//继承Item所有属性
constructor(private data: asd[]) {}
getItem(index: number): string {
return this.data[index].name;
}
}
const data = new DataManager([{ name: "dell" }]);
data.getItem(0);
// 声明类型 使用泛型作为一个具体的类型注解
function hello<T>(params: T) {
return params;
}
const func: <T>(param: T) => T = hello;
// const func: <ABC>(param:ABC) => string = <ABC>() => {
// return "123";
// };
// 泛型约束
interface IWithlength{
length:number
}
function name<T extends IWithlength>(arg:T):T {
console.log(arg.length)
return arg
}
const arrs=name([1,2,3])
const arrd=name({length:10,width:10})
const str=name('str')
namespace
namespace Components {
export class Header {
constructor() {
const elem = document.createElement("div");
elem.innerHTML = "This is Header";
document.body.appendChild(elem);
}
}
export class Content {
constructor() {
const elem = document.createElement("div");
elem.innerHTML = "This is content";
document.body.appendChild(elem);
}
}
export class Footer {
constructor() {
const elem = document.createElement("div");
elem.innerHTML = "This is Footer";
document.body.appendChild(elem);
}
}
}
namespace Home {
//命名空间
export class Page {
//把page输出 暴露出去
constructor() {
new Components.Header();
new Components.Content();
new Components.Footer();
}
}
}
泛型keyof
interface Person {
name: string;
age: number;
gender: string;
}
// type T = "name";
// key: 'name';
// Person['name'];
// type T = 'age'
// key: 'age';
// Person['age']
class Teacher {
constructor(private info: Person) {}
getInfo<T extends keyof Person>(key: T): Person[T] {
return this.info[key];
}
}
const teacher = new Teacher({
name: "dell",
age: 18,
gender: "male",
});
const test = teacher.getInfo("age");
console.log(test);
