Mastering Assembly Programming

Data types and their definitions

Before we start working with Assembly instructions, we have to know how to define data, or, to be more precise, how to tell the assembler which type of data we are using.

The Flat Assembler supports six built-in types of data and allows us to either define or declare variables. The difference between a definition and a declaration in this case is that when we define a variable we also assign a certain value to it, but when we declare, we simply reserve space for a certain type of data:

Variable definition format: [label] definition_directive value(s)

• label: This is optional, but addressing an unnamed variable is harder

Variable declaration format: [label] declaration_directive count

• label: This is optional, ...