arraylist-ArrayList底層的動態數組怎麼實現？

ArrayList底層的動態數組怎麼實現？

數組怎麼實現動態分配長度？數組的長度為什麼不固定？求大神講解

最佳回答：

沒有動態，最終還是數組復制，小數組換大數組

//這是數據擴充的核心代碼，最終就是arrays.copyof
 private void grow(int minCapacity) {
         // overflow-conscious code
         int oldCapacity = elementData.length;
         int newCapacity = oldCapacity + (oldCapacity >> 1);
         if (newCapacity - minCapacity < 0)
             newCapacity = minCapacity;
         if (newCapacity - MAX_ARRAY_SIZE > 0)
             newCapacity = hugeCapacity(minCapacity);
         // minCapacity is usually close to size, so this is a win:
         elementData = Arrays.copyOf(elementData, newCapacity);
     }