java中遍历MAP的几种方法

 

转载地址：http://hi.baidu.com/zhangxia6110/blog/item/517f5a23ba9d965e9922ed36.html

 

Java代码

1. Map<String,String> map=new HashMap<String,String>();
2. map.put("username","qq");
3. map.put("passWord","123");
4. map.put("userID","1");
5. map.put("email","[e-mail]");

Map<String,String> map=new HashMap<String,String>();map.put("username", "qq");map.put("passWord", "123");map.put("userID", "1");map.put("email", "[e-mail]");

第一种用for循环
Java代码

1. for(Map.Entry<String, String> entry:map.entrySet()){
2. System.out.println(entry.getKey()+"--->"+entry.getValue());
3. }

for(Map.Entry<String, String> entry:map.entrySet()){          System.out.println(entry.getKey()+"--->"+entry.getValue()); }

第二种用迭代
Java代码

1. Set set = map.entrySet();
2. Iterator i = set.iterator();
3. while(i.hasNext()){
4. Map.Entry<String, String> entry1=(Map.Entry<String, String>)i.next();
5. System.out.println(entry1.getKey()+"=="+entry1.getValue());
6. }

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
Java代码

1. Iterator it=map.keySet().iterator();
2. while(it.hasNext()){
3. String key;
4. String value;
5. key=it.next().toString();
6. value=map.get(key);
7. System.out.println(key+"--"+value);
8. }

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
Java代码

1. Iterator it=map.entrySet().iterator();
2. System.out.println( map.entrySet().size());
3. String key;
4. String value;
5. while(it.hasNext()){
6. Map.Entry entry = (Map.Entry)it.next();
7. key=entry.getKey().toString();
8. value=entry.getValue().toString();
9. System.out.println(key+"===="+value);
10. }