let someArray = [1, "string",false];for(let entry of someArray) { console.log(entry);//1, "string", false} 二、for..in 方法 这个方法要注意和for..of的区别,for..in遍历的值是数组的索引 let list = [4, 5, 6];//for infor(let iinlist) { console.log(i);//"0", "1", "2...
["DOM", "ES2015", "ScriptHost","ES2019.Array"], // TS需要引用的库,即声明文件,es5 默认引用dom、es5、scripthost,如需要使用es的高级版本特性,通常都需要配置,如es8的数组新特性需要引入"ES2019.Array", "allowJS": true, // 允许编译器编译JS,JSX文件 "checkJs": true, // 允许在JS文件中报错...
functionsanitizeFoo(checker:any){if(typeofchecker.number!="number"||typeofchecker.boolean!="boolean"||(checker.maybeString!=undefined&&typeofchecker.maybeString!="string")||!sanitizeBar(checker.bar)){returnfalse;}returntrue;}functionsanitizeBar(checker:any){if(!sanitizenumberArray(checker.numbers)...
interfaceAdmin{name:string;privileges:string[];}interfaceEmployee{name:string;startDate:Date;}type UnknownEmployee=Employee|Admin;functionprintEmployeeInformation(emp:UnknownEmployee){console.log("Name: "+emp.name);if("privileges"inemp){console.log("Privileges: "+emp.privileges);}if("startDate"inemp...
(args);}showType({id:1,name:'test'});// Output: {id: 1, name: "test"}functionshowTypeTwo(args:GenericType<string,string[]>){console.log(args);}showTypeTwo({id:'001',name:['This','is','a','Test']});// Output: {id: "001", name: Array["This", "is", "a", "Test"...
functionprintValueLater(value: string | undefined) {if(value ===undefined) { value ="missing!"; } setTimeout(()=>{// Modifying 'value', even in a way that shouldn't affect// its type, will invalidate type refinements in closures.value = value; ...
export class Photo { id: number name: string description: string filename: string views: number isPublished: boolean }And you want to store photos in your database. To store things in the database, first, you need a database table, and database tables are created from your models. Not...
declare module "libname" { // Types inside here export function helloWorldMessage(): string; } Test editing an existing package You can edit the types directly in node_modules/@types/foo/index.d.ts to validate your changes, then bring the changes to this repo with the steps below. Alternat...
比如 声明一个变量 var arr ,要判断arr是不是数组,可以使用arr instanceof Array 同理,假设有个类型 TestType type TestType = { name:string, age:number } 1. 2. 3. 4. 想判断某个类型是不是 TestType类型,我们可以如下使用 type TestType = { ...
TypeScript 包含各种基本类型，例如 Number、Array、Tuple、Boolean、String 等等。好吧，其中一些类型在 ...