java 遍历对象

最新推荐文章于 2024-09-15 10:41:50 发布

archfree

最新推荐文章于 2024-09-15 10:41:50 发布

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CC 4.0 BY-SA版权

文章标签： java hashmap iterator object import string

本文链接：https://blog.youkuaiyun.com/archfree/article/details/6028680

以下通过程序来简单实践一下HashMap的的遍历
PS：如果要保持HashMap的遍历顺序和原插入顺序一致，可以使用LinkedHashMap，使用方法和HashMap一样，改一下声明即可：LinkedHashMap myMap = new LinkedHashMap(); 当然需要导入：java.util.LinkedHashMap

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

public class MapList {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
HashMap myMap = new HashMap();
myMap.put("hello", "你好");
myMap.put("bye", "再见");
myMap.put("thanks", "谢谢");
myMap.put("ok", "好的");
System.out.println("--------------------遍历key和value----------------------");
for(Iterator iter = myMap.entrySet().iterator();iter.hasNext();){
            Map.Entry element = (Map.Entry)iter.next();
            Object strKey = element.getKey();
            Object strObj = element.getValue();
            System.out.println("myMap.get(/""+strKey+"/")="+strObj);
}
System.out.println();
System.out.println("--------------------遍历整个HashMap----------------------");
Collection objs = myMap.entrySet();
for (Iterator iterator=objs.iterator(); iterator.hasNext();){
   Object obj = iterator.next();
   System.out.println(obj);
}
System.out.println();
System.out.println("--------------------遍历HashMap的key----------------------");
Collection keys = myMap.keySet();
for (Iterator iterator=keys.iterator(); iterator.hasNext();){
   Object key = iterator.next();
   System.out.println(key);
}
System.out.println();
System.out.println("--------------------遍历HashMap的value----------------------");
Collection values = myMap.values();
for (Iterator iterator=values.iterator(); iterator.hasNext();){
   Object value = iterator.next();
   System.out.println(value);
}
}
}
运行结果：
--------------------遍历key和value----------------------
myMap.get("hello")=你好
myMap.get("thanks")=谢谢
myMap.get("ok")=好的
myMap.get("bye")=再见