如何在java中取map中的鍵值?有哪兩種方法？

Map map = new HashMap();\x0d\ map.put("1", "value1");\x0d\ map.put("2", "value2");\x0d\ map.put("3", "value3");\x0d\ \x0d\ //第壹種：普遍使用，二次取值\x0d\ System.out.println("通過Map.keySet遍歷key和value：");\x0d\ for (String key : map.keySet()) {\x0d\ System.out.println("key= "+ key + " and value= " + map.get(key));\x0d\ }\x0d\ \x0d\ //第二種\x0d\ System.out.println("通過Map.entrySet使用iterator遍歷key和value：");\x0d\ Iterator> it = map.entrySet().iterator();\x0d\ while (it.hasNext()) {\x0d\ Map.Entry entry = it.next();\x0d\ System.out.println("key= " + entry.getKey() + " and value= " + entry.getValue());\x0d\ }\x0d\ \x0d\ //第三種：推薦，尤其是容量大時\x0d\ System.out.println("通過Map.entrySet遍歷key和value");\x0d\ for (Map.Entry entry : map.entrySet()) {\x0d\ System.out.println("key= " + entry.getKey() + " and value= " + entry.getValue());\x0d\ }\x0d\\x0d\ //第四種\x0d\ System.out.println("通過Map.values()遍歷所有的value，但不能遍歷key");\x0d\ for (String v : map.values()) {\x0d\ System.out.println("value= " + v);\x0d\ }\x0d\ }