Typescript 指北
官方文档
https://www.tslang.cn/docs/handbook/basic-types.html
快速开始
安装
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| npm install -g typescript
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编译
查看版本
基础类型
布尔值
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| let isDone: boolean = false;
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数字
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| let decLiteral: number = 6;
let hexLiteral: number = 0xf00d;
let binaryLiteral: number = 0b1010;
let octalLiteral: number = 0o744;
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模板字符串
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| let name: string = "bob";
let age: number = 37;
let sentence: string = `Hello, my name is ${ name }.
I'll be ${ age + 1 } years old next month.`;
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数组
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| let list: number[] = [1, 2, 3];
let list: Array<number> = [1, 2, 3];
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元组 Tuple
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| let x: [string, number];
x = ["hello", 10]; // OK
x = [10, "hello"]; // Error
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枚举
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| enum Color {Red, Green, Blue}
let c: Color = Color.Green;
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Any
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| let notSure: any = 4;
notSure = "maybe a string instead";
notSure = false; // okay, definitely a boolean
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Void
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| function warnUser(): void {
console.log("This is my warning message");
}
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Null 和 Undefined
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| let u: undefined = undefined;
let n: null = null;
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Never
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| // 返回never的函数必须存在无法达到的终点
function error(message: string): never {
throw new Error(message);
}
// 推断的返回值类型为never
function fail() {
return error("Something failed");
}
// 返回never的函数必须存在无法达到的终点
function infiniteLoop(): never {
while (true) {
}
}
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接口
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| interface Parent {
name: string
age: number
}
interface child extends Parent {
address: string
}
const jibao:child = {
name: 'wangjingdong',
age: 5,
address: 'xi`an'
}
console.log(jibao.name)
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类
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| class Article {
public title: string // 公共
public detail?: string
readonly author: string | number = 'Jonh' // 只读
// private intro?: string // 私有
protected protectedData?: string // 内部受保护的
// static 静态，是给类的本身，而不是类的实例
// private protected privateProtectedData: string = 'privateProtectedData'
constructor (title: string, detail: string ) {
this.title = title
this.detail = detail
}
}
const bookA = new Article('传奇', '在那段战火纷飞,饱受苦难的年代，有一位伟大的地主家儿子......')
console.log(bookA.author)
class Mao extends Article {
public role: string
constructor (title: string, detail: string, role: string) {
super(title, detail)
this.role = role
}
}
const mao = new Mao('传奇', '在那段战火纷飞,饱受苦难的年代，有一位伟大的地主家儿子......', 'Mr mao')
console.log(mao)
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存储器属性
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| class User {
private _password: string = ''
get password (): string {
return '******' // this._password
}
set password (value: string) {
this._password = value
}
}
const userA = new User()
console.log(userA.password)
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抽象类
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| <blockquote>用来作为子类基类去使用，规范格式的</blockquote>
abstract class Animal {
name: string
constructor (name: string) {
this.name = name
}
abstract sayHi (): void
}
class Dog extends Animal {
constructor (name: string) {
super(name)
}
sayHi (): void {
console.log('汪汪汪')
}
}
const dog = new Dog('旺财')
dog.sayHi()
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类实现接口
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| interface Fruit {
color: string
get taste(): string
}
interface Banana {
price: number
}
/** 如果使用继承extends,则无法同时继承多个类 */
class Apple implements Fruit, Banana {
color: string = 'red'
price: number = 100
get taste() {
return ''
}
}
const apple = new Apple()
console.log(apple)
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class myClass<T> {
public value: T
constructor (value: T) {
this.value = value
}
processData (input: T):T {
console.log(this.value)
return input
}
}
const myClassA = new myClass<string>('一年级')
console.log(myClassA.processData('二年级'))
const myClassB = new myClass<number>(1)
console.log(myClassB.processData(2))
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__END__
