源碼:public static native void arraycopy(Object src, int srcPos, Object dest, int destPos,int length);
參數:
src:要複製的數組(源數組)
srcPos:複製源數組的起始位置
dest:目標數組
destPos:目標數組的下標位置
length:要複製的長度
例如:
String[] arr = {"A","B","C","D","E","F"};
System.arraycopy(arr ,3,arr,2,2);
從下標爲3的位置開始複製,複製的長度爲2(複製D、E),從下標爲2的位置開始替換爲D、E
複製後的數組爲:
String[] arr = {"A","B","D","E","E","F"};
ArrayList的remove()和add(int ?,object ?)都是是根據此方法進行的操作。