Java Term of the Week: Octal

Following on with the numbering system theme it's time to look at octal numbers. Unlike denary numbers they only use the digits 0,1,2,3,4,5,6,7 and have a base of 8.

What this means is that to represent a value of 8 octal numbers use two digits 10. If that seems hard to understand think about the denary system you're used to. 10 in the denary system is the same as saying 1xTens + 0xOnes, 11 is 1xTens + 1xOnes and so on. The difference with octal numbers is that we're dealing with a base of 8. Therefore, 10 in octal is 1xEights + 0xOnes (i.e., 8), 11 is 1xEights + 1xOnes (i.e., 9).

These days it's unlikely that you'll actually use octal numbers. They were originally used as a compact way of representing bits. Once computer architectures based themselves around bytes, octal numbers were found to be inefficient in converting binary numbers.