Java中遍历容器List、Map、Set的方法总结

List

List<String> list = new ArrayList<>();
        list.add("张三");
        list.add("李四");
        list.add("王五");
        //遍历List
        //方式一：for循环
        System.out.print("for循环遍历List:");
        for (int i = 0; i < list.size(); i++) {
            System.out.print(list.get(i));
        }
        System.out.println();
        //方式二:增强型for循环
        System.out.print("增强型for循环遍历List:");
        for (String str :
                list) {
            System.out.print(str);
        }
        System.out.println();
        //方式三:Iterator迭代器方式遍历
        //for循环方式
        System.out.print("Iterator迭代器遍历List（for循环）:");
        for (Iterator<String> iterator = list.iterator();iterator.hasNext();){
            System.out.print(iterator.next());
        }
        System.out.println();
        //while循环方式
        System.out.print("Iterator迭代器遍历List（while循环）:");
        Iterator<String> iterator = list.iterator();
        while(iterator.hasNext()){
            System.out.print(iterator.next());
            iterator.remove();  //如果想一边遍历一边删除，建议使用此种方式
        }

Set

Set<String> set = new HashSet<>();
        set.add("one");
        set.add("two");
        set.add("three");
        set.add("four");
        //遍历Set
        //方式一：增强型for循环(底层用HashMap实现不能用简单for循环)
        System.out.print("增强型for循环遍历Set:");
        for (String str :
                set) {
            System.out.print(str);
        }
        System.out.println();
        //方式二：迭代器Iterator
        System.out.print("Iterator迭代器遍历Set:");
        for (Iterator<String> iteraotr = set.iterator();iteraotr.hasNext();){
            System.out.print(iteraotr.next());
        }   //while循环一样

Map

 //遍历Map
        Map<Integer,String> map = new HashMap<>();
        map.put(1,"张三");
        map.put(2,"李四");
        map.put(3,"王五");
        map.put(4,"赵六");
        System.out.println();
        //通过keySet方式
        System.out.print("keySet方法遍历Map:");
        Set<Integer> tmp = map.keySet();
        for (Iterator<Integer> iterator1 = tmp.iterator();iterator1.hasNext();){
            Integer key = iterator1.next();
            System.out.print(key+"-->"+map.get(key));
        }
        System.out.println();
        //通过entrySet方式
        System.out.print("entrySet方法遍历Map:");
        Set<Map.Entry<Integer,String>> t = map.entrySet();
        for (Iterator<Map.Entry<Integer,String>> iterator1 = t.iterator();iterator1.hasNext();){
            Map.Entry<Integer,String> entry = iterator1.next();
            System.out.print(entry.getKey()+"-->"+entry.getValue());
        }