Typescript -如何使用泛型来定义返回对象的可索引属性的函数？

function getObject<T>(): T {
  // 函数体
}

function getObject<T>(): T {
  let obj: T = {} as T;
  // 对象的属性赋值
  return obj;
}

function getObject<T, K extends keyof T>(key: K): T[K] {
  let obj: T = {} as T;
  // 对象的属性赋值
  return obj[key];
}

interface Person {
  name: string;
  age: number;
}

function getObject<T, K extends keyof T>(obj: T, key: K): T[K] {
  return obj[key];
}

const person: Person = {
  name: "John",
  age: 30
};

const name = getObject(person, "name"); // 类型推断为string
const age = getObject<Person, "age">(person, "age"); // 显式指定泛型参数