When you need the contents of an array for processing, you no longer have to write loops to copy the required contents from the main to the sub-array. Java has provided an API for this task?the arraycopy method in the System class.

The method takes five arguments:

1. src: The source array.
2. srcPosition: The position in the source from where you wish to begin copying.
3. des: The destination array.
4. desPosition: The position in the destination array to where the copy should start.
5. length: The number of elements to be copied.

This method throws a NullPointerException if either of src or des are null.

It also throws an ArrayStoreException in the following cases:

• If the src is not an array.
• If the des is not an array.
• If src and des are arrays of different data types.