functionfn1(){return[Promise.resolve(1),Promise.resolve(2)];}functionfn2(){return[1,2];} 在这里顺带一提,对Array.map的每一项进行异步等待的方法: 代码语言:javascript 复制 awaitPromise.all(arr.map(asyncitem=>{returnawaititem.run();})); 如果为了执行顺序,可以换成for..of的语法,因为数组类型...
To avoid.thenchains withPromises, JavaScript users often introduced anasyncfunction in order to useawait, and then immediately called the function after defining it.
promise, async和await 2019-12-10 14:14 −最开始实现异步的方法:回调函数 method1(function(err, result) { if (err) { throw err; } method2(function(err, result) { if (err) { throw err; ... pei~乐悠悠 0 1955 TypeScript-1
declare function MaybePromise<T>(value: T): T | Promise<T> | PromiseLike<T>; async function doSomething(): Promise<[number, number]> { const result = await Promise.all([ MaybePromise(100), MaybePromise(200) ]); // Error! // // [number | Promise<100>, number | Promise<200>]...
asyncfunctionfetchData():Promise<string>{return"Data";}typeAwaitedData=Awaited<ReturnType<typeoffetchData>>;// AwaitedData 的类型为 string 在上述代码中,Awaited<ReturnType<typeof fetchData>>获取了 fetchData 函数返回 Promise 的解析值类型。
const Class: { new(): IClass; }: Prefer to use a class declaration class Class { constructor(); } instead of a new-able constant. getMeAT<T>(): T: If a type parameter does not appear in the types of any parameters, you don't really have a generic function, you just have a ...
以上实例定义了一个类 Site,该类有一个方法 name(),该方法在终端上输出字符串 Runoob。 new 关键字创建类的对象,该对象调用方法 name()。 编译后生成的 JavaScript 代码如下: var Site = /** @class */ (function () { function Site() { } Site.prototype.name = function () { console.log("Runoob...
When calling generic functions, TypeScript is able to infer type arguments from whatever you pass in. Copy functiondoSomething<T>(arg: T){// ...}// We can explicitly say that 'T' should be 'string'.doSomething<string>("hello!");// We can also just let the type of 'T' get infe...
UserSchema.static('login',async function(this:any,username:string,password:string){ let user=await this.findOne({username}) if(user){ const match =await bcryptjs.compare(password,user.password) if(match){ return user }else{ return null ...
async function fetchApi<ResultType>(path: string): Promise<ResultType>{ const response = await fetch(`https://example.com/api${path}`); return response.json(); } 突出显示的代码将您的函数转换为接受 ResultType 泛型类型参数的泛型函数。此泛型类型用于函数的返回类型:Promise。 注意:由于您的函数是异...