HashMap
-
//基於JDK1.8版本以上 lambada函數
map.forEach((k, v) -> {
System.out.println("key:value = " + k + “:” + v);
if (k.equals(“test”)) {
//map.put(k, JsonUtil.fromJson((String) v, List.class));
}
}); -
//keySet獲取map集合key的集合 然後在遍歷key即可
for(String key:map.keySet()){
String value = map.get(key).toString();//
System.out.println(“key:”+key+" vlaue:"+value);
} -
//Map集合循環遍歷方式三 推薦,尤其是容量大時
Iterator<Entry<String, Object>> it = map.entrySet().iterator();
while(it.hasNext()){
Entry<String, Object> entry = it.next();
System.out.println(“key:”+entry.getKey()+" key:"+entry.getValue());
} -
// Map集合循環遍歷方式三 推薦,尤其是容量大時
for (Map.Entry<String, Object> m : map.entrySet()) {
System.out.println(“key:” + m.getKey() + " value:" + m.getValue());
} -
//通過Map.values()遍歷所有的value,但不能遍歷key
for(Object m:map.values()){
System.out.println(m);
}