// 通过接口(interface) 声明对象类型interfaceInfoType{readonlyname:string// 只读属性age?:number// 可选属性height:number}// 指定对象的类型constinfo:InfoType= {name:'zhangsan',age:20,height:170}console.log(info.name);// info.name = '
// eslint 报错信息:// 'myNane' is not defined.eslint(no-undef)console.log(`My name is${myName.toStrng()}`);// tsc 报错信息:// Property 'toStrng' does not exist on type 'string'. Did you mean 'toString'? 上例中,我们使用了var来定义一个变量,但其实 ES6 中有更先进的语法let和c...
If we end up reaching for the value of this type, we’ll end up with string | any, which is just any. Copy function* uppercase(iter: Iterator<string, any>) { while (true) { const { value, done } = iter.next(); yield value.toUppercase(); // oops! forgot to check for `done...
functiongetResult(input:string):numberfunctiongetResult(input:number):stringfunctiongetResult<T>(input:T):TfunctiongetResult(input:any):any{if(typeofinput==='string')returninput.lengthelseif(typeofinput==='number')returninput.toString()elsereturninput} 前三行组成了函数重载,第四行开始是实际函数体...
Deno 长期以来一直在考虑将程序编译成可执行文件的可能性,而这种可执行文件可以在没有外部依赖项的情况下运行,就像 Go 一样,不过现在还没有正式提上日程(https://github.com/denoland/deno/issues/986)。这将改变游戏规则。 没有包管理器 没有包管理器并且必须依靠 URL 来承载和导入包有利有弊。我真的很喜欢...
export function SayHello(name : string) : void { ShowGreeting("Hello ", name); } export function SayGoodbye(name : string) : void { ShowGreeting("Sorry to see you go ", name); } function ShowGreeting(text : string, name : string) : void { console.log(text + name + "!"); } ...
let notSure: any = 4; notSure = 'maybe a string instead'; 注意:any类型是多人协作项目的大忌,很可能把TypeScript变成AnyScript,除非不得已,不应首先考虑使用此类型。 unknown unknown是TypeScript3.0引入的新类型,是any类型对应的安全类型。 他们的共同点是,可以被赋值任何类型的值。
In TypeScript, a union type variable is a variable which can store multiple type of values (i.e. number, string etc). A union type allows us to define a variable with multiple types. The union type variables are defined using the pipe (‘|’) symbol between the types. The union types...
// used to trigger the snippet and the body will be expanded and inserted. Possible variables are: // $1, $2 for tab stops, $0 for the final cursor position, and ${1:label}, ${2:another} for placeholders. // Placeholders with the same ids are connected. ...
letmessage: string ='Hello World,This is a typescript!,涂聚文 Web'; document.body.innerHTML = message; const hello : string ="Hello World,This is a typescript!,涂聚文,hi." console.log(hello) //https://code.visualstudio.com/docs/typescript/typescript-debugging ...