Set的5种遍历方式

逃离我推掉我的手 2024-04-18 20:53 66阅读 0赞

package com.akaiqi.chun.test;

import java.util.\*;

public class testSet \{

public static void main(String[] args) {
        List<Integer> list = new ArrayList<>(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12));
        Set<Integer> sets = new HashSet<>(16);
        sets.addAll(list);
    
        //遍历1： foreach
        System.out.println("\n遍历1： foreach:");
        for (Integer i : sets) {
            System.out.print(i + " ");
        }
    
        //遍历2： iterator
        System.out.println("\n遍历2： iterator:");
        Iterator<Integer> iterator = sets.iterator();
        while (iterator.hasNext()) {
            System.out.print(iterator.next() + " ");
        }
    
        //遍历3： stream流
        System.out.println("\n遍历3： stream流");
        sets.forEach(s -> System.out.print(s + " "));
    
        //遍历4：for循环
        System.out.println("\n遍历4：for循环");
        Iterator<Integer> iterator2 = sets.iterator();
        for (int i = 0; i < sets.size(); i++) {
            System.out.print(iterator2.next() + " ");
        }
    	// forEachRemaining:底层实现while (hasNext()) action.accept(next());  
    	System.out.println("\n遍历5：forEachRemaining");
        sets.iterator().forEachRemaining(s -> System.out.print(s + " "));
    
    }

结果：

遍历1： foreach:
    1 2 3 4 5 6 7 8 9 10 11 12 
    遍历2： iterator:
    1 2 3 4 5 6 7 8 9 10 11 12 
    遍历3： stream流
    1 2 3 4 5 6 7 8 9 10 11 12 
    遍历4：for循环
    1 2 3 4 5 6 7 8 9 10 11 12 
    遍历5：forEachRemaining
    1 2 3 4 5 6 7 8 9 10 11 12 
    Process finished with exit code 0