map的几种遍历方式_对map进行遍历

(4) 2024-06-12 15:12

Hi,大家好,我是编程小6,很荣幸遇见你,我把这些年在开发过程中遇到的问题或想法写出来,今天说一说
map的几种遍历方式_对map进行遍历,希望能够帮助你!!!。

//循环遍历map的方法 public class MapF { public static void main(String[] args) { Map<String, Integer> tempMap = new HashMap<String, Integer>(); tempMap.put("a","12"); tempMap.put("b","34"); tempMap.put("c","56"); // JDK1.4中 // 遍历方法一 hashmap entrySet() 遍历 Iterator it = tempMap.entrySet().iterator(); while (it.hasNext()) { Map.Entry entry = (Map.Entry) it.next(); Object key = entry.getKey(); Object value = entry.getValue(); System.out.println("key=" + key + " value=" + value); } System.out.println(""); // JDK1.5中,应用新特性For-Each循环 // 遍历方法二 for (Map.Entry<String, Integer> entry : tempMap.entrySet()) { String key = entry.getKey().toString(); String value = entry.getValue().toString(); System.out.println("key=" + key + " value=" + value); } System.out.println(""); // 遍历方法三 hashmap keySet() 遍历 for (Iterator i = tempMap.keySet().iterator(); i.hasNext();) { Object obj = i.next(); System.out.println(obj);// 循环输出key System.out.println("key=" + obj + " value=" + tempMap.get(obj)); } for (Iterator i = tempMap.values().iterator(); i.hasNext();) { Object obj = i.next(); System.out.println(obj);// 循环输出value } // 遍历方法四 treemap keySet()遍历 for (Object o : tempMap.keySet()) { System.out.println("key=" + o + " value=" + tempMap.get(o)); } System.out.println("11111"); // java如何遍历Map <String, ArrayList> map = new HashMap <String, // ArrayList>(); System.out.println("java 遍历Map <String, ArrayList> map = new HashMap<String, ArrayList>();"); Map<String, ArrayList> map = new HashMap<String, ArrayList>(); Set<String> keys = map.keySet(); Iterator<String> iterator = keys.iterator(); while (iterator.hasNext()) { String key = iterator.next(); ArrayList arrayList = map.get(key); for (Object o : arrayList) { System.out.println(o); } } Map<String, List> map = new HashMap<String, List>(); for (Map.Entry entry : map.entrySet()) { String key = entry.getKey().toString(); List<String> list= (List) entry.getValue(); for (String value : list) { System.out.println(key + "====" + value); } } } } 

今天的分享到此就结束了,感谢您的阅读,如果确实帮到您,您可以动动手指转发给其他人。

上一篇

已是最后文章

下一篇

已是最新文章

发表回复