let map:Map<string, string> = { [ "key1": "hello world 1" ], ["key2": "hello world 2"] } ; alert( JSON.stringify(map.get("key")) ); 我得到的例外如下。 VM133:4 Uncaught TypeError: map.get is not a function at eval (eval at exec (typescript.js:41), <anonymous>:4:26...
Map不是原语，需要用构造函数来调用(我认为Typescript应该对此进行警告)。
Issue description or question Hello, I ran into a problem while testing out the new es2019 features. I get an error when I try to use the flatMap method Sample code const nestedWords = [['one', 'two', ['three']] const flatten = nestedWor...
Removing a package When a package bundles its own types, types should be removed from Definitely Typed to avoid confusion. You can remove it by running pnpm run not-needed <typingsPackageName> <asOfVersion> [<libraryName>]. <typingsPackageName>: This is the name of the directory to delete....
在TypeScript中,下面两个例子都是一样的会报a.getName is not a function错误。 首先我们使用 class 定义一个类 C,使用 extends 继承原生构造函数 Array,那么类 C 创建的实例就能继承所有 Array 原型对象上的方法,比如 map、filter 等。我们先来看代码: class C extends Array { getName() { return "liao...
这里的实体主要分为2种，一种是数据库访问层的实体Domain，直接用来定义某个数据库表的实体，里面定义的...
function evaluatePrice(vehicle: Vehicle) { return vehicle.capacity * EVALUATION_FACTOR; } const myTruck: Truck = { vType: "truck", capacity: 9.5 }; evaluatePrice(myTruck); 对于以上代码,TypeScript 编译器将会提示以下错误信息: Property 'capacity' does not exist on type 'Vehicle'. ...
functionTSButton(){letname:string="Fred";document.getElementById("ts-example").innerHTML = greeter(user); }classStudent { fullName:string;constructor(publicfirstName:string,publicmiddleInitial:string,publiclastName:string) {this.fullName = firstName +" "+ middleInitial +" "+ lastName; } }in...
This is not a TypeScript tutorial. It is highly recommended that you review the TypeScript tutorial material and Get Started pages. There are many advantages to using TypeScript. Its primary function is identifying type errors before the code runs, which is often referred to as static type ...
functiongetUrls(url: string | URL, names: string[]){if(typeofurl==="string") {url=newURL(url); }returnnames.map(name => {url.searchParams.set("name", name)// ~~~// error!// Property 'searchParams' does not exist on type 'string | URL'.returnurl.toString(); }); } Here,...