1. Map<String, String> map = new HashMap<String, String>();
2. map.put("key1", "value1");
3. map.put("key2", "value2");
4. map.put("key3", "value3");
6. //第一種：普遍使用，二次取值
7. System.out.println("通過Map.keySet遍歷key和value：");
8. for (String key : map.keySet()) {
9. System.out.println("key= "+ key + " and value= " + map.get(key));
10. }
12. //第二種
13. System.out.println("通過Map.entrySet使用iterator遍歷key和value：");
14. Iterator<Map.Entry<String, String>> it = map.entrySet().iterator();
15. while (it.hasNext()) {
16. Map.Entry<String, String> entry = it.next();
17. System.out.println("key= " + entry.getKey() + " and value= " + entry.getValue());
18. }
20. <span style="color:#FF0000;"> //第三種：推薦，尤其是容量大時</span>
21. System.out.println("通過Map.entrySet遍歷key和value");
22. for (Map.Entry<String, String> entry : map.entrySet()) {
23. System.out.println("key= " + entry.getKey() + " and value= " + entry.getValue());
24. }
26. //第四種
27. System.out.println("通過Map.values()遍歷所有的value，但不能遍歷key");
28. for (String v : map.values()) {
29. System.out.println("value= " + v);
30. }

轉載： https://blog.csdn.net/h378588270/article/details/23271733

Map<String, String> 遍歷的四種方法