轉JSONObject put,accumulate,element的區別

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  public Object put (Object key, Object value) 將value映射到key下。如果此JSONObject對象之前存在一個value在這個key下，當前的value會替換掉之前的valueAssociates the specified value with the specified key in this map(optional operation). If the map previously contained . a mapping for this key, the old value is replaced by the specified value. (A map m is said to contain a mapping for a key k if and only if m.containsKey(k) would return true .)) public JSONObject accumulate (String key, Object value) 累積value到這個key下。這個方法同element()方法類似，特殊的是，如果當前已經存在一個value在這個key下那麼一個JSONArray將會儲存在這個key下來儲存所有累積的value。如果已經存在一個JSONArray，那麼當前的value就會添加到這個JSONArray中。相比之下replace方法會替代先前的valueAccumulate values under a key. It is similar to the element method except that if there is already an object stored under the key then a JSONArray is stored under the key to hold all of the accumulated values. If there is already a JSONArray, then the new value is appended to it. In contrast, the replace method replaces the previous value. public JSONObject element (String key, Object value) 將鍵/值對放到這個JSONObject對象裡面。如果當前value為空白(null)，那麼如果這個key存在的話，這個key就會移除掉。如果這個key之前有value值，那麼此方法會調用accumulate()方法。Put a key/value pair in the JSONObject. If the value is null, then the key will be removed from the JSONObject if it is present. If there is a previous value assigned to the key, it will call accumulate.

轉JSONObject put,accumulate,element的區別