TS 小记 | 哈哈哈哈哈

keyof

interface Point {
  a: string;
  b: string;
}

type Pk = keyof Point;

const age: Pk = 'b';

type OptionsFlags<T> = {
  [key in keyof T]: boolean;
};

type Name = OptionsFlags<{ name: 1; age: 11 }>;

// type Name = {
//     name: boolean;
//     age: boolean;
// }

keyof 作用于 object 的类型，并将其 key 值转换为联合类型

typeof

用户获取变量的类型

function showName() {
  return {
    name: 133,
  };
}

type P = ReturnType<typeof showName>;

// type P = {
//   name: number;
// };

const info = ['school', 'age'] as const;
type Info = typeof info[number];
// type Info = "school" | "age"

keyof​

typeof​

keyof

typeof