学习笔记之集合ArrayList(1)和迭代器

import java.util.ArrayList;
import java.util.List;
import java.util.ListIterator;

public class TestDemo {

    public static void main(String[] args) {
        List<Integer> list = new ArrayList<Integer>();
        list.add(1);
        list.add(5);
        list.add(2);
        list.add(4);
        list.add(3);
        System.out.println("----------for循环-----------");
        int size = list.size();
        for(int i=0;i<size;i++){
            System.out.print(list.get(i)+" ");
        }
        System.out.println();
        System.out.println("--------for each 循环--------");
        for(int a:list){
            System.out.print(a+" ");
        }
        System.out.println();
        System.out.println("-------单项迭代器---------");
        java.util.Iterator<Integer> it = list.iterator();
        while(it.hasNext()){
            System.out.print(it.next() + " ");
        }
        System.out.println();
        
        System.out.println("--------双向迭代器---------");
        ListIterator<Integer> lte = list.listIterator();
        while(lte.hasNext()){
            System.out.print(lte.next() + " ");
        }
        System.out.println();
        
        while(lte.hasPrevious()){
            System.out.print(lte.previous()+" ");
        }
    }

}