问题
I know that you can create a string in nasm by writing this:
mystring db 'Hello World'
But if I want to move a single character, let's say e, the second character in the string to the al register. How can I do that? Should I write
mov al, mystring+1
or something? And how do I make an int variable? Can I write:
myint db 4
回答1:
'mystring + 1' is the address of the second byte of the string.
mov al, mystring + 1
stores (the least significant byte of) that address in al. To indicate that you don't want to store the address but the byte located at that address, write this:
mov al, [mystring + 1]
To declare a four-bytes integer equal to say, 42, use:
myint dd 42
来源：https://stackoverflow.com/questions/30082772/nasm-variable-basics