是什么？

typeof 用于获取变量的类型，或者变量的类型，所以 typeof 后面始终是跟着一个变量。

  1. interface Person {
  2.   name: string;
  3.   age: number;
  4.   isChina: boolean;
  5. }
  7. let me: Person = {
  8.   name: 'stone',
  9.   age: 18,
  10.   isChina: true
  11. }
  13. type handsome = typeof me;
  14. // type handsome = Person
  1. interface Person {
  2.   name: string;
  3.   age: number;
  4.   isChina: boolean;
  5. }
  7. let me: Person = {
  8.   name: 'stone',
  9.   age: 18,
  10.   isChina: true
  11. }
  13. type handsome = typeof me;
  14. // type handsome = Person
  16. const colorObj = {
  17.   red: 'red',
  18.   yellow: 'yellow',
  19. };
  21. type colorType = keyof typeof colorObj;
  22. // type colorType = "red" | "yellow"
  23. let color: colorType;
  24. // let color: "red" | "yellow"
  25. color = 'red';
  26. color = 'yellow';
  27. // color = 'blue';
  28. // 不能将类型“"blue"”分配给类型“"red" | "yellow"”。ts(2322)