關Map遍歷取值解決辦法
阿新 • • 發佈:2018-11-30
常用的幾種方式:
Map<String, String> map = new HashMap<String, String>();
//第一種:普遍使用,二次取值 for (String key : map.keySet()) { System.out.println("key= "+ key + " and value= " + map.get(key)); } //第二種 Iterator<Map.Entry<String, String>> it = map.entrySet().iterator(); while (it.hasNext()) { Map.Entry<String, String> entry = it.next(); System.out.println("key= " + entry.getKey() + " and value= " + entry.getValue()); } //第三種:推薦,尤其是容量大時 for (Map.Entry<String, String> entry : map.entrySet()) { System.out.println("key= " + entry.getKey() + " and value= " + entry.getValue()); } //第四種 for (String v : map.values()) { System.out.println("value= " + v); } }