1.1 TypeScript 安装与调试

安装

npm install typescript@2.9.2 -g
npm install ts-node@7.0.0 -g

调试

1. 安装 vscode，command + K、command + S 自定义格式化按键

2. 创建 ts 文件

3. 在目录下新建 /.vscode/launch.json，这样 vscode 就可以用 ts-node 调试了

    {
        "configurations": [
            {
            "name": "ts-node",
            "type": "node",
            "request": "launch",
            "program": "/usr/local/bin/ts-node",
            "args": ["${relativeFile}"],
            "cwd": "${workspaceRoot}",
            "protocol": "inspector"
            }
        ]
    }
   

官方 5 分钟文档

1. 函数可以添加类型注解

   function greeter(person: string) {
       return 'Hello, ' + person
   }
   
   let user = 'Dolores_2B'
   
   console.log(greeter(user))
   

• 注意：如果传的是非 string 类型，编译时会报错
• 如果传的是 undefined，编译也会通过

2. 接口

   interface Person {
       firstName: string
       lastName: string
   }
   
   function greeter(person: Person) {
       return 'Hello, ' + person.firstName + ' ' + person.lastName
   }
   
   let user = {
       firstName: 'Dolores',
       lastName: '2B'
   }
   console.log(greeter(user))
   

   enum Gender {
       Male,
       Female
   }
   
   interface Person {
       gender: Gender
   }
   
   function merry(a: Person, b: Person): [Person, Person] {
       if (a.gender !== b.gender) {
           return [a, b]
       }else {
           throw new Error('性别相同不能结婚')
       }
   }
   
   let a = {
       gender: Gender.Male
   }
   let b = {
       gender: Gender.Male
   }
   console.log(merry(a, b))
   

3. 函数的重载

   function add(a: string, b: string)
   function add(a: number, b: number)
   function add(a: any, b: any): any {
       return a + b
   }
   console.log(add('Dolores', 1))