Declare an object inside or outside a loop?

Question

Is there any performance penalty for the following code snippet?

for (int i=0; i         


        

Answer 1

I've actually in front of me a code which looks like this:

for (int i = offset; i < offset + length; i++) {
    char append = (char) (data[i] & 0xFF);
    buffer.append(append);
}
...
for (int i = offset; i < offset + length; i++) {
    char append = (char) (data[i] & 0xFF);
    buffer.append(append);
}
...
for (int i = offset; i < offset + length; i++) {
    char append = (char) (data[i] & 0xFF);
    buffer.append(append);
}

So, relying on compiler abilities, I can assume there would be only one stack allocation for i and one for append. Then everything would be fine except the duplicated code.

As a side note, java applications are known to be slow. I never tried to do profiling in java but I guess the performance hit comes mostly from memory allocation management.