list,set,map集合的遍历

package com.test;

import java.awt.List;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

/**
 * list集合遍历  set集合遍历  hashmap集合遍历
 * 
 * @author 18430
 *
 */

public class Test {
	public static void main(String[] args) {

		Student student1 = new Student("zhangsan", 90);
		Student student2 = new Student("lisi", 78);
		Student student3 = new Student("wangwu", 56);

		ArrayList<Student> list = new ArrayList<Student>();
		list.add(student1);
		list.add(student2);
		list.add(student3);

		for (int i = 0; i < list.size(); i++) {
			System.out.print(list.get(i));
		}
		System.out.println();
		System.out.println("for循环遍历list================================================");

		//
		Iterator iterator = list.iterator();
		while (iterator.hasNext()) {
			System.out.print(iterator.next());
		}

		System.out.println();
		System.out.println("迭代器遍历list================================================");

		//
		for (Student student : list) {
			System.out.print(student);
		}

		System.out.println();
		System.out.println("foreach遍历list================================================");

		HashSet<Student> set = new HashSet<>();
		set.add(student1);
		set.add(student2);
		set.add(student3);

		for (Student student : set) {
			System.out.print(student);
		}

		System.out.println();
		System.out.println("foreach遍历set================================================");

		Iterator iterator1 = set.iterator();
		while (iterator1.hasNext()) {
			System.out.print(iterator1.next());
		}

		System.out.println();
		System.out.println("迭代器遍历set================================================");

		HashMap map = new HashMap();
		map.put("1", student1);
		map.put("2", student2);
		map.put("3", student3);

		Iterator iterator3 = map.keySet().iterator();
		while (iterator3.hasNext()) {
			System.out.println(map.get(iterator3.next()));
		}

		System.out.println();
		System.out.println("map集合的遍历================================================");

	}

}

  

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转载自www.cnblogs.com/yanweichen/p/9281594.html