java中遍历MAP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", "[email protected]");   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());   
}
 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());   
}   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);   
}  

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);                    
}