1. 程式人生 > >Map的三種遍歷方式

Map的三種遍歷方式

package com.qf.day13;

import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

public class work9 {
    public static void main(String[] args) {
        Map<String, Object> map=new HashMap<>();
for(int i=0;i<10;i++){ map.put(""+i, i); } System.out.println("用Map的內部類Entry,來遍歷Map集合"); Set<Entry<String, Object>> entrySet = map.entrySet(); for(Entry<String,Object> entry:entrySet){ System.out.println(entry.getKey
()+"-"+entry.getValue()); } System.out.println("利用迭代器,遍歷Map集合"); Iterator<String> iterator=map.keySet().iterator(); while(iterator.hasNext()){ String id=iterator.next(); System.out.println(id+"-"+map.get(id)); } System.out
.println("遍歷values"); Collection<Object> collection=map.values(); for(Object object:collection){ System.out.println(object); } } }