java遍歷Map方法彙總

Map遍歷Itearator分兩種，第一種是使用entryset方法直接獲取<key.value>,第二種是使用set獲取key，再通過key獲取value；具體代碼如下：

public class TestItearator {
	public static void main(String[] args) {
		testIteratorMap();	
	}
	//map
	public static void testIteratorMap() {
		Map<Integer,String> map1=new HashMap<>();
		map1.put(100, "a");
		map1.put(200, "vv");
		map1.put(300, "cc");
		//第一種遍歷Map
		Set<Entry<Integer,String>> ss=map1.entrySet();
		for(Iterator<Entry<Integer,String>>iter=ss.iterator();iter.hasNext();) {
			Entry<Integer, String> temp=iter.next();
			System.out.println(temp.getKey()+"----"+temp.getValue());
		}
		System.out.println("++++++++++++++++++++++++++++++++++++++++++");
		//第二種遍歷
		Set<Integer> keySet=map1.keySet();
		for(Iterator<Integer> iter=keySet.iterator();iter.hasNext();) {
			Integer key=iter.next();
			System.out.println(key+"____"+map1.get(key));
		}
	}