Order in which instructions are printed/executed

Why the output is in diffrent order than it is declared?

Shouldnt the output be in this order?

aaaa bbbb cccc

Instead it is:

I assume the issue is in assigning "bbb" value to the text variable, but i dont know why is that and how to do this the correct way.

Instructions:

    section .data
text db "aaaa", 10
text2 db "cccc", 10

section .text
    global _start

_start:
    mov rax, text
    call _printstring
   
    mov rax, "bbb"
    mov [text], rax
   
mov rax, text
    call _printstring

mov rax, text2
call _printstring

    mov eax, 60
    xor edi, edi
    syscall

_printstring:
push rax
mov rbx, 0
_printstringloop:
inc rax
inc rbx
mov cl, [rax]
cmp cl, 0
jne _printstringloop

mov rax, 1
mov rdi, 1
pop rsi
mov rdx, rbx
syscall

ret

Shouldnt the output be in this order?

aaaa bbbb cccc

Not with this code.

What happens here is that this string is printed first: "aaaa\ncccc\n"

_printstring does not stop at the newline, it goes all the way to the zero terminator, which wasn't explicit in the strings but there is apparently some zero-fill after the data, as usual, but in general you may not want to rely on that.

Then:

mov rax, "bbb"
mov [text], rax

So after that, "bbb" (no newline) is printed, as observed. This also nukes the contents of text2, since it's an 8 byte store and the last 3 of those 8 bytes are the first 3 bytes of text2, and those bytes are zero so printing text2 doesn't result in any printable text (presumably a zero character is printed, but it's invisible)