Difference between %assign and %define [duplicate]

Question

What is the difference between %assign and %define in NASM assembly x86? Because for me it looks like they are the same thing, well, not really. Is %assign just a %define for which you can change later in the code?

Answer 1

They are not part of x86 assembly, they’re specific to nasm. They’re similar but not quite: %assign defines a numeric constant and it can be redefined. It cannot take arguments.%define defines a numeric or string valued macro, it can take arguments, and can also be redefined.

More information in the documentation