What are the benefits of byte as a datatype?

Answer 1

A byte is the smallest unit of addressable storage. Although a bit is smaller than a byte, a single bit cannot be addressed directly; we always deal with groups of bits and a byte is the smallest group of bits that can be physically addressed. However, once we have addressed a byte, we can then examine the individual bits within it using the bitwise logic operators (AND, OR, NOT and XOR).

On most systems a byte is exactly 8 bits in length. The reason for this is simply that we can represent any 8-bit value using a convenient two-digit hexadecimal notation, where each hex digit represents exactly 4-bits (often called a nybble because it is half-a-byte). Thus an 8-bit byte can be represented by any hexadecimal value in the range 0x00 to 0xff (or 0 to 255 decimal).

(Some systems use odd-size bytes, such as a 9-bit byte. For this we typically use 3-digit octal notation because an octal digit represents exactly 3 bits. Such systems are rare, but we sometimes come across other odd-sized bytes, especially in older data transfer systems such as dot-matrix printers which utilised a 7-bit byte. However, in modern architecture, we can safely say that a byte is always at least 8 bits long.)

Not all programming languages utilise a byte data type as such. C, for instance, doesn't have a built in byte data type but it does have a char data type which is always 1 byte in length. There's no real reason why there isn't a byte data type in C, but when all data types are measured in terms of bytes it was probably deemed unnecessary to say that a byte is 1 byte in length. Although a char is typically used to encode a single character from a character set (and has built in overloads specific to that purpose), the encoding is no less numeric than a byte would be, so there was no real need for a separate byte data type.

Although a single byte can represent any decimal value in the range 0 to 255, it is more correct to say that a single byte can represent any one of 256 unique abstractions. Whether it is a single character from a character set, an unsigned value in the range 0 to 256, or a signed value in the range -128 to +127, these are merely abstractions. How abstractions are interpreted is entirely down to the programmer and/or the programming language.