Copying arrays in java

ArrayCopy

System.arraycopy(from, fromIndex, to, toIndex, count);

eg. System.arraycopy(arr1, 2, arr2, 3, 4);
The shallowcopy starts at position 2 in the source array i.e. arr1 and copies four entries, starting at position 3 of the target array i.e. arr

CopyOf

arr2 = Arrays.copyOf(a, newLength);

New shallow copy of array with new length. If longer, uses default values.

copyOfRange

arr2 = Arrays.copyOfRange(a, from, to);

New shallow copy of portion of array.