遍历Arraylist的几种方法

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

public class Ergodic { 
   
public static void main(String[] args) { 
   

	System.out.println("ArrayList集合的遍历");
	List list = new ArrayList();
	list.add(1);
	list.add(2);

	
	System.out.println("1.for循环:");
	for(int i = 0; i<list.size(); i++) { 
   
		System.out.println(list.get(i));
	}

	
	System.out.println("2.foreach循环:");
	for(Object l : list) { 
   
		System.out.println(l);
	}

	
            System.out.println("3.链表变为数组内容后遍历:");
            Integer[] inteArray = new Integer[list.size()];
            list.toArray(inteArray);
            for(int inte : inteArray) { 
   
                System.out.println(inte);
            }


	System.out.println("4.while迭代器遍历:");
	Iterator iterator1 = list.iterator();
	while(iterator1.hasNext()) { 
   // hasNext()方法:判断该指针所指位置是否有元素
		System.out.println(iterator1.next());// next()方法:1.获取该指针指向的元素 2.并把指针指向下一个元素(即指针后移一位)
	}


	System.out.println("5.for迭代器遍历:");
	//该处将while改为for循环遍历,可以当遍历完后便释放迭代器对象,更节省内存
	for(Iterator iterator3 = list.iterator(); iterator3.hasNext() ;) { 
   
		System.out.println(iterator3.next());
	}

	
	System.out.println("6.1 ListIterator迭代器向后遍历:");
	ListIterator iterator2 = list.listIterator();
	while(iterator2.hasNext()) { 
   // 将list集合先从头向后遍历,指针指向最后
		System.out.println(iterator2.next());
	}


	System.out.println("6.2 ListIterator迭代器向前遍历");
	while(iterator2.hasPrevious()) { 
   // 将list集合从末尾先前遍历,指针指到第一个元素
		System.out.println(iterator2.previous());
	}		
}
}