I have two byte arrays - array1 and array2 . 
My aim is to copy the bytes from 1st array to second with respect to the start index of each array and fill the non filled bytes with a specific byte.

```
byte[] array1 = new byte[5]
The data is as follows: 11,22,00,33,44; 

byte[] array2 = new byte[10];     

```

I need to copy the bytes from array1 to array2. The data needs to be copied from position 3 in array2 and fill the rest of the empty positions with value ff.
ie my result in array2 would be {ff,ff,ff,11,22,00,33,44,ff,ff}

Any help would be appreciable.

Thanks in advance!