Java，使用迭代器搜索 ArrayList 并删除匹配的对象

2022-01-10 00:00:00 iterator java foreach-loop-container

基本上，用户提交一个字符串，迭代器在 ArrayList 中搜索该字符串.找到后，迭代器将删除包含该字符串的对象.

Basically, the user submits a String which the Iterator searches an ArrayList for. When found the Iterator will delete the object containing the String.

因为这些对象中的每一个都包含两个字符串，所以我很难将这些行写成一个.

Because each of these objects contain two Strings, I am finding trouble writing these lines as one.

Friend current = it.next();
String currently = current.getFriendCaption();

感谢您的帮助！

推荐答案

你不需要它们在一行，只要在匹配时使用 remove 删除一个项目:

You don't need them on one line, just use remove to remove an item when it matches:

Iterator<Friend> it = list.iterator();
while (it.hasNext()) {
    if (it.next().getFriendCaption().equals(targetCaption)) {
        it.remove();
        // If you know it's unique, you could `break;` here
    }
}

完整演示:

import java.util.*;

public class ListExample {
    public static final void main(String[] args) {
        List<Friend>    list = new ArrayList<Friend>(5);
        String          targetCaption = "match";

        list.add(new Friend("match"));
        list.add(new Friend("non-match"));
        list.add(new Friend("match"));
        list.add(new Friend("non-match"));
        list.add(new Friend("match"));

        System.out.println("Before:");
        for (Friend f : list) {
            System.out.println(f.getFriendCaption());
        }

        Iterator<Friend> it = list.iterator();
        while (it.hasNext()) {
            if (it.next().getFriendCaption().equals(targetCaption)) {
                it.remove();
                // If you know it's unique, you could `break;` here
            }
        }

        System.out.println();
        System.out.println("After:");
        for (Friend f : list) {
            System.out.println(f.getFriendCaption());
        }

        System.exit(0);
    }

    private static class Friend {
        private String friendCaption;

        public Friend(String fc) {
            this.friendCaption = fc;
        }

        public String getFriendCaption() {
            return this.friendCaption;
        }

    }
}

输出:

$ java ListExample 
Before:
match
non-match
match
non-match
match

After:
non-match
non-match

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