java遍历集合的四种方法

1.迭代器 2.foreach 3.toArray() 4.size()和get()

	public static void main(String[] args) {
		//创建集合
		List list = new ArrayList();
		
		//添加元素
		list.add("1");
		list.add(1, "123");
		list.add(2, "345");
		list.add(3, "678");
		list.add(4, "678");
		
		//方式一：foreach
		for (Object obj : list) {
			System.out.print(obj + " ");
		}
		System.out.println();
		
		//方式二：转成数组
		Object[] oarr = list.toArray();
		for (int i = 0; i < oarr.length; i++) {
			System.out.print(oarr[i]+" ");
		}
		System.out.println();
		
		//方式三：size()和get()
		for(int i = 0; i<list.size();i++) {
			System.out.print(list.get(i) +" ");
		}
		System.out.println();
		
		//方式四:迭代器
		Iterator<String> it = list.iterator();
		while(it.hasNext()) {
			System.out.print(it.next() +" ");
		}
	}