map遍历方法

java中遍历MAP的几种方法
Java代码

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]");  

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



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

Java代码



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

Java代码



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

Java代码



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);                    

}