java中增强for循环

@Test
	public void test2() {
		List list = new ArrayList();
		list.add(1);
		list.add(2);
		list.add(3);
		list.add(4);
		
		for(Object num : list){
			int i = (Integer) num;
			System.out.print(i+" ");
		}
	}
	
	@Test
	public void test3() {
		//Map map = new HashMap();
		Map map = new LinkedHashMap();
		
		map.put("1", "aaa");
		map.put("2", "bbb");
		map.put("3", "ccc");
		map.put("4", "ddd");
		
		Set set = map.keySet();
		Iterator it = set.iterator();
		while(it.hasNext()){
			String key = (String) it.next();
			String value = (String) map.get(key);
			System.out.println(key + "=" + value);
		}
	}
}

注意 只能取数据，不能改变数组货集合的数据