生僻操作

• 接口合并重载

//声明相同接口时会合并，此时相当于声明了两个createFnc属性（重载）
interface face {
    createFnc(name: string): (number: number) => number
}
interface face {
    createFnc(namx: number): (string: string) => number
}

//实现重载可以用联合属性
createFnc(name: string | number): (number: number | string) => number {
        return (num: number) => num + 20;
 }

• 命名空间合并

export namespace aaa {
    export const ccc = "Aa";
    const dd = "dd";
   
}
export namespace aaa {
    // 此处访问不到dd因为不共享相同命名空间中未导出的声明
    export let saydd = () => {
        console.log(dd);
    }
}