package com;
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;
/**
* 遍历Map
* @author Administrator
*/
public class IterateMapKey {
public static void main(String[] args) {
Map<String,Integer> map = new HashMap<String,Integer>();
//添加3个元素
map.put("k1", 1);
map.put("k2", 2);
map.put("k3", 3);
System.out.println("-----获取所有的key------");
Set<String> keys = map.keySet();
for( String key : keys ){
System.out.println("key:" + key+",value:"+ map.get(key));
}
System.out.println("-----获取所有 key-value------");
//java.util.Map.Entry
Set<Entry<String,Integer> > entries = map.entrySet();
//获取用于遍历Set集合的迭代器
Iterator<Entry<String,Integer>> it = entries.iterator();
while(it.hasNext()){
//遍历每一组键值对
Entry<String,Integer> entry = it.next();
String key = entry.getKey();
int value = entry.getValue();
System.out.println(key+"="+value);
}
System.out.println("-----返回的所有value不是存入的Set集合------");
Collection<Integer> values = map.values();
for(Integer value : values){
System.out.println("value:"+value);
}
}
}