java 遍歷MAP的幾種辦法示例代碼

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java中遍歷MAP的幾種辦法

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"); 

第一種用for輪回

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()); 
} 

第二種用迭代

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);           
}  

 

 以上就是對Java 遍歷MAP的材料整頓，後續持續彌補相干材料，感謝年夜家對本站的支撐！