参考文章:
Java遍历Map集合的四种方式
迭代器Iterator与for循环的区别
Map<String, String> map = new HashMap<String, String>(); map.put("key1", "value1"); map.put("key2", "value2"); //方法一: for (Map.Entry<String, String> entry : map.entrySet()) { //获取key值 String mapKey = entry.getKey(); //获取value值 String mapValue = entry.getValue(); //结果:key1:value1 key2:value2 System.out.println(mapKey + ":" + mapValue); } //方法二: // 遍历获取key值 for (String key : map.keySet()) { //结果 key1 key2 System.out.println(key); } // 遍历获取value值 for (String value : map.values()) { //结果:value1 value2 System.out.println(value); } //方法三: Iterator<Entry<String, String>> entries = map.entrySet().iterator(); while (entries.hasNext()) { Entry<String, String> entry = entries.next(); //获取key值 String key = entry.getKey(); //获取value值 String value = entry.getValue(); //结果:key1:value1 key2:value2 System.out.println(key + ":" + value); } //方法四: //根据遍历得出的key值获取value值 for(String key : map.keySet()){ //获取value值 String value = map.get(key); //结果:key1:value1 key2:value2 System.out.println(key+":"+value); }
for 和 Iterator的选择问题,在参考文章 迭代器Iterator与for循环的区别 中已经有详细的对比,如果想详细了解,可看参考文章内容