• expand
    • 签名: expand(project: function, concurrent: number, scheduler: Scheduler): Observable
  • 递归调用提供的函数
    • 示例
      • 示例 1: 每次调用加1
  • 相关食谱
  • 其他资源

    expand

    签名: expand(project: function, concurrent: number, scheduler: Scheduler): Observable

    递归调用提供的函数

    expand - 图1

    示例

    示例 1: 每次调用加1

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    1. import { interval } from 'rxjs/observable/interval';
    2. import { of } from 'rxjs/observable/of';
    3. import { expand, take } from 'rxjs/operators';
    5. // 发出 2
    6. const source = of(2);
    7. const example = source.pipe(
    8.   // 递归调用提供的函数
    9.   expand(val => {
    10.     // 2,3,4,5,6
    11.     console.log(`Passed value: ${val}`);
    12.     // 3,4,5,6
    13.     return of(1 + val);
    14.   }),
    15.   // 用5次
    16.   take(5)
    17. );
    18. /*
    19.     "RESULT: 2"
    20.     "Passed value: 2"
    21.     "RESULT: 3"
    22.     "Passed value: 3"
    23.     "RESULT: 4"
    24.     "Passed value: 4"
    25.     "RESULT: 5"
    26.     "Passed value: 5"
    27.     "RESULT: 6"
    28.     "Passed value: 6"
    29. */
    30. // 输出: 2,3,4,5,6
    31. const subscribe = example.subscribe(val => console.log(`RESULT: ${val}`));

    相关食谱

    • 游戏循环

    其他资源

    • expand :newspaper: - 官方文档

    :file_folder: 源码: https://github.com/ReactiveX/rxjs/blob/master/src/internal/operators/expand.ts