/*
 * public static void arraycopy(Object src, int srcPos,
 *                  Object dest, int destPos, int length)
 * 
 * Parameters: 
 * -----------
 * 
 * src - the source array. 
 * srcPos - starting position in the source array. 
 * dest - the destination array.
 * destPos - starting position in the destination data.
 * length - the number of array elements to be copied.
 */

public class ArrayCopyDemo
{

    public static void main(String[] args)
    {
        int srcArray[] =
        { 30, 40, 50 };
        int destArray[] =
        { 1, 2, 3, 4 };

        System.out.print("Before copy, destArray = ");
        for (int i : destArray)
        {
            System.out.print(i + ",");
        }

        /*
         * Copies an array from the specified source array,
         * beginning at the specified position, to the
         * specified position of the destination array.
         */
        System.arraycopy(srcArray, 0, destArray, 0, 3);
        System.out.print("\nAfter copy, destArray = ");
        for (int i : destArray)
        {
            System.out.print(i + ",");
        }

    }
}

Before copy, destArray = 1,2,3,4,
After copy, destArray = 30,40,50,4,