What does the parameter of system.arraycopy mean in Java?

In Java, the System.arraycopy() method is used to copy a portion of one array into another array. The parameters are as follows:

1. Original array (Object src): the original array to be copied.
2. The initial position of the original array (int srcPos): specifies the starting index in the original array to be copied.
3. Destination array (Object dest): The array where the original array is to be copied.
4. The starting position (int destPos) of the target array: specifies the starting index in which the original array will be copied to the target array.
5. Number of elements to copy (int length): Specifies the number of elements to copy.

Note: When copying elements, the target array must be large enough to accommodate the elements being copied. If the target array is not large enough to hold all elements, only the number of elements that can be accommodated will be copied.

For example, the following code will copy 3 elements starting from the second position in the original array arr to the fourth position in the target array dest:

int[] arr = {1, 2, 3, 4, 5};
int[] dest = new int[7];
System.arraycopy(arr, 1, dest, 3, 3);

After copying is completed, the destination array dest will become {0, 0, 0, 2, 3, 4, 0}.