集合类的各种实现类使用迭代器迭代的具体写法

集合类的各种实现类使用迭代器迭代的具体写法

enum Color {RED,
    YELLOW;
}
public class T {
/**
 * @param args
 */
public static void main(String[] args) {
        HashSet<String> hashSet = new HashSet<String>();
        System.out.println("HashSet的Iterator：" + hashSet.iterator()
);
       LinkedHashSet<String> linkedHashSet = new LinkedHashSet<String>();
        System.out.println("LinkedHashSet的Iterator：" +
            linkedHashSet.iterator());

        TreeSet<String> treeSet = new TreeSet<String>();
        System.out.println("TreeSet的Iterator：" + treeSet.iterator());

        EnumSet<Color> enumSet = EnumSet.allOf(Color.class);
        System.out.println("EnumSet的Iterator：" + enumSet.iterator());

        ArrayList<String> arrayList = new ArrayList<String>();
        System.out.println("ArrayList的Iterator`这里写代码片`：" + arrayList.iterator());

        Vector<String> vector = new Vector<String>();
        System.out.println("Vector的Iterator：" + vector.iterator());

        LinkedList<String> linkedList = new LinkedList<String>();
        System.out.println("LinkedList的Iterator：" + linkedList.iterator());

        ArrayDeque<String> arrayDeque = new ArrayDeque<String>();
        System.out.println("ArrayDeque的Iterator：" + arrayDeque.iterator());
    }
}

遍历输出方式(例如LinkedList())

第一种

    public static void main(String[] args) {

        List<Integer> list = new LinkedList<>();
for (int i = 0; i < 10; i++) {
            list.add(i);
        }
        Iterator iterator = list.iterator();
while (iterator.hasNext()) {
            System.out.println(iterator.next());

        }

    }

第二种

public static void main(String[] args) {

        List<Integer> list = new LinkedList<>();
for (int i = 0; i < 10; i++) {
            list.add(i);
        }
        Iterator<Integer> iterator = list.iterator();
for (; iterator.hasNext();) {
            System.out.println(iterator.next());

        }

    }

第三种

    public static void main(String[] args) {

        List<Integer> list = new LinkedList<>();
for (int i = 0; i < 10; i++) {
            list.add(i);
        }
for (Iterator<Integer> it = list.iterator(); it.hasNext();) {
            System.out.println(it.next());

        }
    }