代码很简单哈,算是对基础知识的一个总结和回顾吧,先上代码:
/** * Map集合的几种遍历方式 * @author wxh * @vertion 1.0 */ public class DemoMap { private static Map<Integer,String> getMap() { Map<Integer,String> map = new HashMap<Integer,String>(); map.put( 1, "wxh1" ); map.put( 2, "wxh2" ); map.put( 3, "wxh3" ); map.put( 4, "wxh4" ); return map; } /** * 直接遍历 */ @Test public void test01() { Set<Entry<Integer, String>> set = getMap().entrySet(); Iterator<Entry<Integer, String>> it = set.iterator(); while( it.hasNext() ) { Entry<Integer, String> e = it.next(); System.out.println( e.getKey() + "==" + e.getValue() ); } } /** * 用增强for循环遍历 */ @Test public void test02() { for( Entry<Integer, String> e : getMap().entrySet() ) { System.out.println( e.getKey() + "==" + e.getValue() ); } } /** * 根据key获取value */ @Test public void test03() { Set<Integer> set = getMap().keySet(); Iterator<Integer> it = set.iterator(); while( it.hasNext() ) { Integer key = it.next(); String value = getMap().get( key ); System.out.println( key + "==" + value ); } } /** * 通过增强for循环根据key获取value */ @Test public void test04() { for( Integer key : getMap().keySet() ) { String value = getMap().get( key ); System.out.println( key + "==" + value ); } } }