这里有新鲜出炉的Java设计模式,程序狗速度看过来!
java 是一种可以撰写跨平台应用软件的面向对象的程序设计语言,是由Sun Microsystems公司于1995年5月推出的Java程序设计语言和Java平台(即JavaEE(j2ee), JavaME(j2me), JavaSE(j2se))的总称。
本文主要介绍java 遍历MAP的知识资料,这里整理几种方法及实现示例代码,有兴趣的小伙伴可以参考下
java中遍历MAP的几种方法
- Map<String,String> map=new HashMap<String,String>();
- map.put("username", "qq");
- map.put("passWord", "123");
- map.put("userID", "1");
- map.put("email", "qq@qq.com");
- Map<String,String> map=new HashMap<String,String>();
- map.put("username", "qq");
- map.put("passWord", "123");
- map.put("userID", "1");
- map.put("email", "qq@qq.com");
第一种用for循环
- for (Map.Entry < String, String > entry: map.entrySet()) {
- System.out.println(entry.getKey() + "--->" + entry.getValue());
- }
- for (Map.Entry < String, String > entry: map.entrySet()) {
- System.out.println(entry.getKey() + "--->" + entry.getValue());
- }
第二种用迭代
- Set set = map.entrySet();
- Iterator i = set.iterator();
- while(i.hasNext()){
- Map.Entry<String, String> entry1=(Map.Entry<String, String>)i.next();
- System.out.println(entry1.getKey()+"=="+entry1.getValue());
- }
- Set set = map.entrySet();
- Iterator i = set.iterator();
- while(i.hasNext()){
- Map.Entry<String, String> entry1=(Map.Entry<String, String>)i.next();
- System.out.println(entry1.getKey()+"=="+entry1.getValue());
- }
用keySet()迭代
- Iterator it = map.keySet().iterator();
- while (it.hasNext()) {
- String key;
- String value;
- key = it.next().toString();
- value = map.get(key);
- System.out.println(key + "--" + value);
- }
- Iterator it = map.keySet().iterator();
- while (it.hasNext()) {
- String key;
- String value;
- key = it.next().toString();
- value = map.get(key);
- System.out.println(key + "--" + value);
- }
用entrySet()迭代
- Iterator it = map.entrySet().iterator();
- System.out.println(map.entrySet().size());
- String key;
- String value;
- while (it.hasNext()) {
- Map.Entry entry = (Map.Entry) it.next();
- key = entry.getKey().toString();
- value = entry.getValue().toString();
- System.out.println(key + "====" + value);
- }
来源: http://www.phperz.com/article/17/1118/360035.html