遍历list集合：

 

遍历map集合：遍历map集合有以下几种方式。

package asi;import java.util.Iterator;import java.util.Map;import java.util.HashMap;public class TestMapBianLi {    //for遍历key public void test1(Map
     
       map){      for(String key:map.keySet()){   System.out.println("test1(): "+key);  } } //for循环遍历value public void test2(Map
      
        map){  for(String value:map.values()){   System.out.println("test2(): "+value);  } }  //for循环遍历entrySet，获取key和value public void test3(Map
       
         map){  for(Map.Entry
        
          entry:map.entrySet()){   System.out.println("test3(): "+entry.getKey()+":"+entry.getValue());  } } //用Iterator遍历 public void test4(Map
         
           map){  Iterator
          
           
            > it= map.entrySet().iterator(); while(it.hasNext()){ Map.Entry
            
              entry=it.next(); System.out.println("test4():"+entry.getKey()+":"+entry.getValue()); } } public static void main(String[] args){ Map
             
               map=new HashMap
              
               (); map.put("a", "aa"); map.put("b", "bb"); map.put("c", "cc"); TestMapBianLi t=new TestMapBianLi(); t.test1(map); t.test2(map); t.test3(map); t.test4(map); } }
              
             
            
           
          
         
        
       
      
     

 

输出结果为：

test1(): b

test1(): c

test1(): a

test2(): bb

test2(): cc

test2(): aa

test3(): b:bb

test3(): c:cc

test3(): a:aa

test4():b:bb

test4():c:cc

test4():a:aa