Iterable ?????? ?? ??? ?? ???? ???? ??? ??? ????? ???? ?????. ??: Iterable ??? ????. Iterator ??? ?????. ???? ?????(hasNext ? next ??? ??). ??: ??? ?? ??. ?? ???? ??????. ????? ?????.

Java?? Iterable ????? ??

Iterable ????? ??

Iterable ?????? ???? ??? ???? ?? ???? ???? ?? ??? ?? ???? ?????. ??? ??? Iterable? ???? ???? ? ??? ??? ???? ? ????.

Usage

Iterable ?????? ????? ?? ??? ??? ???.

1. Iterable ?? ??: Iterable ?????? ???? ???? ????? ??? List, Set, Map? ?? ??? ???? ?????.
2. Iterator ?? ????: Iterable ???? Iterator ??? ????? iterator() ???? ?????. iterator() 方法從 Iterable 對(duì)象獲取一個(gè) Iterator 對(duì)象。
3. 遍歷集合： 使用 hasNext() 方法檢查是否有更多元素，并使用 next()

hasNext() ???? ???? ?? ??? ??? ???? next() ???? ???? ?? ??? ?????.

?:

// 創(chuàng)建一個(gè)實(shí)現(xiàn)了 Iterable 接口的類
class MyIterable implements Iterable<Integer> {
    private int[] arr;

    public MyIterable(int[] arr) {
        this.arr = arr;
    }

    @Override
    public Iterator<Integer> iterator() {
        return new MyIterator(arr);
    }

    // 自主定義 Iterator 類
    private class MyIterator implements Iterator<Integer> {
        private int index = 0;

        @Override
        public boolean hasNext() {
            return index < arr.length;
        }

        @Override
        public Integer next() {
            return arr[index++];
        }
    }
}

public class Main {
    public static void main(String[] args) {
        int[] myArray = {1, 2, 3, 4, 5};
        MyIterable iterable = new MyIterable(myArray);

        // 使用 for-each 循環(huán)遍歷集合
        for (int num : iterable) {
            System.out.println(num);
        }
    }
}

??

• Iterable ?????? ???? ?? ?? ??? ????.
• ??? ?? ??: Iterable ?????? ???? ?? ?? ??? ?? ??? ?????.
• ?? ???: for-each ?? ??? ?? ? ?? ???? ???? ? ????.

? ??? Java?? iterable? ???? ??? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!