Map、List、Set集合的遍历方法

朴灿烈づ我的快乐病毒、 2022-10-20 13:39 168阅读 0赞

**1、Map集合遍历如下：**

public class TraversingMap { 
        public Map<String,String> getMap(){ 
            Map<String,String> map=new HashMap<>();
            map.put("1","北京");
            map.put("2","河南");
            map.put("3","深圳");
            return map;
        }
        public void traversingMap(Map<String,String> map){ 
            System.out.println("通过Entry遍历<迭代Entry>");
            for(Map.Entry<String,String> entry:map.entrySet()){ 
                System.out.println(entry.getKey()+":"+entry.getValue());
            }
            System.out.println("通过set集合遍历<迭代Set>");
            for(String key:map.keySet()){ 
                System.out.println(key+"："+map.get(key));
            }
        }
    
        public static void main(String[] args) { 
            TraversingMap test=new TraversingMap();
            Map<String,String> map=test.getMap();
            test.traversingMap(map);
        }
    }

**2、 List集合遍历**

public class TraversingList { 
        public List<String> getList(){ 
            List<String> list=new ArrayList<String>();
            list.add("123");
            list.add("456");
            list.add("789");
            list.add("777");
            list.add("888");
            return list;
        }
        public void traversingList(List<String> list){ 
            System.out.println("for循环遍历");
            for (int i = 0; i <list.size() ; i++) { 
                System.out.println(list.get(i));
            }
            System.out.println("Iterator迭代器遍历");
            Iterator<String> iterator=list.iterator();
            while(iterator.hasNext()){ 
                System.out.println(iterator.next());
            }
            System.out.println();
        }
    
        public static void main(String[] args) { 
            TraversingList test=new TraversingList();
            List<String> list=test.getList();
            test.traversingList(list);
        }
    }

**3、Set集合遍历**

public class TraversingSet { 
        public Set<String> getSet(){ 
            Set<String> set=new HashSet<>();
            set.add("123");
            set.add("456");
            set.add("789");
            return set;
        }
        public void traversingSet(Set<String> set){ 
            System.out.println("增强for循环");
            for(String s:set){ 
                System.out.println(s);
            }
            System.out.println("Iterator迭代器遍历");
            Iterator<String> iterator=set.iterator();
            while (iterator.hasNext()){ 
                System.out.println(iterator.next());
            }
        }
    
        public static void main(String[] args) { 
            TraversingSet test=new TraversingSet();
            Set<String> set=test.getSet();
            test.traversingSet(set);
        }
    }