TypeScript 函數類型參數的用法舉例

export type GeneralFunction<T,V> = {
    (name: T, value: V): T
}
      

四種不同的寫法：

const a1: GeneralFunction<string, number> = (a: string, b: number) => a + b;

const a2: GeneralFunction<string, number> = (a, b) => a + b;

const a3 = (a: string, b: number) => a + b;

const a4 = <GeneralFunction<string, number>>((a:string,b:number) => a + b);

console.log(a1('Ethan', 1));
console.log(a2('Ethan', 2));
console.log(a3('Ethan', 3));
console.log(a4('Ethan', 4));
      

其中第三種其實并沒有用到 GeneralFunction 的類型。

編譯錯誤：