log(typeof(id) + ", " + typeof(name)); } displayType<number, string>(1, "Steve"); // number, stringGeneric type can also be used with other non-generic types. Example: Generic with Non-generic Type Copy function displayType<T>(id:T, name:string): void { console.log(typeof(...
zeroValue = 0; myGenericNumber.add = function(x, y) { return x + y; }; 使用示例 代码语言:javascript 代码运行次数:0 运行 AI代码解释 interface Hero { // Hero 接口 id: number; name: string; } getHeroes(): Observable<Hero[]> { return Observable.of([ { id: 1, name: 'Windstorm'...
getProperty(x,"a");//x 里有 a 属性getProperty(x,"m");//报错,x 里没有 m 属性。Argument of type '"m"' is not assignable to parameter of type '"a" | "b" | "c" | "d"'.
letpasscode="Hello TypeScript";classEmployee{private_fullName:string;getfullName():string{returnthis._fullName;}setfullName(newName:string){if(passcode&&passcode=="Hello TypeScript"){this._fullName=newName;}else{console.log("Error: Unauthorized update of employee!");}}}letemployee=newEmployee(...
add('generic') console.log(m.min()) // generic 运行案例 点击"运行案例" 可查看在线运行效果 代码解释: 第2 行,在声明 类MinClass 的后面后加上了 <T>,这样就声明了泛型参数 T,作为一个变量可以是字符串类型,也可以是数字类型。 7. 泛型约束 语法:通过 extends 关键字来实现泛型约束。 如果我们...
classBeeKeeper{hasMask:boolean;}classZooKeeper{nametag:string;}classAnimal{numLegs:number;}classBeeextendsAnimal{keeper:BeeKeeper;}classLionextendsAnimal{keeper:ZooKeeper;}functioncreateInstance<AextendsAnimal>(c:new()=>A):A{returnnewc();}createInstance(Lion).keeper.nametag;// typechecks!createInstance(...
泛型类与泛型接口类似，使用>括起泛型类型，紧跟类名。GenericNumber类的使用直观，并且可能注意到它不限于number类型。也可以使用字符串或其他更复杂类型。与接口一样，直接将泛型类型放在类后面，帮助确认类的所有属性都使用相同的类型。类有两部分：静态部分和实例部分。泛型类指的是实例部分的类型，因此...
get fullName(): string { return this._fullName; } set fullName(newName: string) { if (passcode && passcode == "Hello TypeScript") { this._fullName = newName; } else { console.log("Error: Unauthorized update of employee!"); ...
nametag: string; } class Animal { numLegs: number; } class Bee extends Animal { keeper: BeeKeeper; } class Lion extends Animal { keeper: ZooKeeper; } function createInstance(c: new () => A): A { return new c(); } createInstance(Lion).keeper.nametag; // typechecks!
TypeScript can also infer the type of the generic parameter from the function parameters. ClassesGenerics can be used to create generalized classes, like Map.Example class NamedValue<T> { private _value: T | undefined; constructor(private name: string) {} public setValue(value: T) { this....