函数 forEachRight

  • forEachRight<T>(arr, callbackFn, elseCB?): boolean

  • forEach的反向遍历版本

    类型参数

    • T

    参数

    • arr: ArrayLike<T>
    • callbackFn: ((value: T, index: number, array: ArrayLike<T>) => any)
        • (value, index, array): any

        • 参数

          • value: T
          • index: number
          • array: ArrayLike<T>

          返回 any

    • 可选elseCB: (() => void)
        • (): void

        • 返回 void

    返回 boolean

    示例

    const arr: number[] = [];
    forEachRight([1, 2, 3, 4], (i) => arr.push(i + 1));
    isEqual(arr, [5, 4, 3, 2]); // true

    const result: any = {};
    forEachRight(createArray({ len: 20 }), (v, k) => {
      result[k] = v;
      if (k === 10) return false;
      return;
    });
    isEqual(result,
      createArray({ start: 10, end: 20 }).reduce((obj, v) => {
        obj[v] = v;
        return obj;
      }, {} as Record<string, any>),
    )); // true

    const result2: any[] = [];
    forEachRight(createArray({ len: 20 }), (v, k) => {
      result2.push({ [k]: v });
      if (k === 15) return false;
      return;
    });

    isEqual(result2, [{ 19: 19 }, { 18: 18 }, { 17: 17 }, { 16: 16 }, { 15: 15 }]); // true

    let elseCount = 0;
    const isDone = forEachRight(
      arr,
      () => {},
      () => elseCount++, // 完整遍历以后会执行该方法
    );
    isDone; // true
    elseCount; // 1