1. interface LengthWise {
    2.   length: number;
    3. }
    5. function indentity<T extends LengthWise>(arg: T): T {
    6.   console.log(arg.length);
    7.   return arg;
    8. }
    10. const result = indentity<string>("1212121");
    11. console.log(result);
    13. class GenercNumber<T> {
    14.   zeroValue: T | undefined;
    15.   add: (x: T, y: T) => void | undefined;
    16. }
    17. const myGenericNumber = new GenercNumber<number>();
    18. myGenericNumber.zeroValue = 0;
    19. myGenericNumber.add = function (x, y) {
    20.   return x + y;
    21. };
    23. // 泛型是想函数重载
    25. function getData<T>(value: T): T {
    26.   return value;
    27. }
    28. getData<number>(1212);
    29. getData<string>("1212");
    31. //  泛型 接口
    32. interface ConfigFn {
    33.   <T>(value: T): void;
    34. }
    36. const getData2: ConfigFn = function <T>(value: T): void {
    37.   console.log(value);
    38. };
    40. getData2<number>(2);
    41. getData2<string>("1212");
    43. // 动态泛型
    45. interface Bookmarks {
    46.   msg: string;
    47. }
    49. class BookmarksServers<T extends Bookmarks> {
    50.   items: T[] = [];
    51. }
    52. class BookmarksServers2<T extends Bookmarks = Bookmarks> {
    53.   items: T[] = [];
    54. }
    56. const s = new BookmarksServers2();
    58. // items = [
    59. //   {
    60. //     msg: "223223",
    61. //   },
    62. // ];
    64. let err1: readonly Set<number>;
    65. let err2: readonly Array<number>;
    67. let ok1: readonly boolean[];
    68. let ok2: readonly [number, string];