Question

Is reusing variables a good or bad thing or does it not make a difference?

Should I be doing this:

void someMethod (byte[] arrayOfBytes)
{
   byte[] newArrayOfBytes = someOtherMethod(arrayOfBytes);

   // ...
}

or this:

void someMethod (byte[] arrayOfBytes)
{
   arrayOfBytes = someOtherMethod(arrayOfBytes);

   // ...
}

or does it make no difference at all?

Answer 1

I would not lose any sleep on this. The memory cost of the extra reference variable(s) is negligible. I’d prefer the newArrayOfBytes method just for safety – it’s not considered great practice to reassign a parameter coming into a method and it may lead to bugs later on, when a developer does not realise the parameter has changed to refer to another Object (you’ll see some developers mark the method params as final, to prevent this)