Typescript-基本语法

// 对传入对象的属性约束, 以下是一个约束属性接口
interface User{
    username: string;
    password?: string; // 可选传递
}

function save(user:User):void{
    console.log(user)
}

let info = {
    username: "张三",
    password: "qwe123",
    age: 15     // 额外传递的参数
}
// 传递一个自定义对象的参数需要有必选参数, 其他的属性不会进行检查
save(info)
// 如果直接进行对象传递那么会进行类型的检查
save({
    username: "张三",
    password: "qwe123"
})

// 定义一个函数类型的接口
interface encrypt {
    (key: string, value: string): string;
}
// 既然类型定义为接口类型(参数列表可以不用写类型), 那么就得符合接口的类型
let md5: encrypt = (key, value): string => {
    return `MD5://${key}.${value}`
}
// 发现类型换成any也行, 因为any能接受所有类型
let sha1: encrypt = (key: any, value: any): any => {
    return `SHA1://${key}.${value}`
}
console.log(md5("qwe", "123"))
// 但是发现还是会被类型约束, 所以就算定义了any类型也没有什么起效
// sha1(123, 564) // 错误写法
console.log(sha1("asd", "zxc"))

// 可索引型数组接口, []中为number, 返回值为string
interface CustomArr {
    [index: number]: string;
}
let arr: CustomArr = ['111', '222']
console.log(arr[1])

// 可索引型对象接口, key为string, value为string
interface CustomObj {
    [index: string]: string;
}
let obj: CustomObj = {name: 'zhang', sex: '男'}
console.log(obj['name'])
console.log(obj.sex)

function logProperty(params: string) {
    return function(target: any, attr: any) {
        // 装饰器传递的参数
        console.log(params)
        // 给类的属性挂载数据
        target[attr] = params
    }
}

class HttpClient {
    @logProperty("http://localhost")
    apiUrl: string | undefined;

    getApiUrl() {
        console.log(this.apiUrl)
    }
}

let http: HttpClient = new HttpClient()
http.getApiUrl()

class HttpClient {
    public url: any | undefined;

    @get("http://localhost")
    getData() {
        console.log(this.url);
    }
}

function get(param: string){
    return function(target: any, methodName: any, desc: any){
        console.log(target)
        console.log(methodName)
        console.log(desc)
        // 可以通过类的原型对象target对该实例进行数据挂载
        target.url = param
        target.run = function(){
            console.log('run')
        }
        // 可以修改装饰器所放置方法的实现, 以下的代码就是获取该方法的内容
        console.log(desc.value)
    }
}

let http: any = new HttpClient()
http.getData()
http.run()

function logParams(params: any) {
    return function (target: any, methodName: any, paramsIndex: any) {
        console.log(target);
        console.log(methodName);
        console.log(paramsIndex);
        target.apiUrl = params;
    }
}

class HttpClient {
    getData(name: string, @logParams("10086") uuid: any) {
        console.log(uuid);
    }
}

let http: any = new HttpClient();
http.getData('zhang', 123456);
console.log(http.apiUrl);