Bytes won't be any faster, and they probably won't even save any memory. Even though the
Java language treats them as single bytes, each one will probably be stored in a single
word on in memory--32 or 64 bits.
And even if there was a difference, you wouldn't choose byte over int for something that small, and when there are only 55 of them. Even 55
million ints is easily manageable by a
phone these days. This is not 1970. We don't need to micro-optimize to save every precious byte and CPU cycle.
You choose byte or int for design reasons, not performance reasons. If you want to represent a
number and do
numerical stuff with it--add, subtract, count, etc.--and that number will be an integer, and it will be in the range of roughly +/- 2 billion, then you use an int. If you want to represent an
arbitrary chunk of data that is to be interpreted by some software (your app or another) as on part of a larger whole, such as a piece of an mp3, or part of a Word
doc or a picutre--then you use a byte.