Can't index arrays in assembly

Question

I've been trying to learn some assembly and was testing out arrays and found that when I tried to print out the value at the point indexed nothing happened, after experimenting further it appears that even though I am using the arrays as shown in many examples across the internet, it just simply isn't working

Here's the code:

section .text
    global _start

_start:
    mov eax, num ; eax now contains 5
    mov ebx, [array+8] ; ebx now contains 8
    cmp eax, ebx ; compares eax to ebx
    jge skip ; should not happen because eax is smaller than ebx
    call printdigit
skip:
    call printn
    call _exit

printdigit:
    mov eax, 0x30
    add [num], eax
    mov ecx, num
    mov edx, 1 ;length
    mov ebx, 1 ;write to stdout
    mov eax, 4 ;write call number
    int 0x80
    ret

printn:
    mov eax, 0x0A
    push eax
    mov eax, 4
    mov ebx, 1
    mov ecx, esp
    mov edx, 1
    int 0x80
    add esp, 4
    ret

_exit:
    mov eax, 1
    mov ebx, 0
    int 0x80


section .data
    num dw 5
    array dw 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

The commands I'm using to compile the code

nasm -f elf Bubblesort.asm
ld -m elf_i386 -s -o Bubblesort Bubblesort.o
./Bubblesort

What I'm running:

ubuntu 22.04.3 desktop amd64, (on virtual machine but shouldn't matter I think)

The output I want should be

5

The actual output

I want printdigit to be called only when num is less than whatever is indexed at array

I am almost certain its not a computer issue but a code issue but I'm unsure where

I have now done the following changes

_start:
   mov eax, [num]
   mov ebx, [array+8]
   cmp eax, ebx
   jae skip

section .data
    num dd 5
    array dd 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

the rest of the code is as normal

this now prints the value i want when array is indexed to a value greater than num, but when it isn't greater it still prints the value

Answer 1

Solution:

section .text
    global _start

_start:
    mov eax, [num]
    movzx ebx, word [array+12]
    cmp eax, ebx
    jb skip
    call printdigit
    jmp exit
skip:
    call printn
exit:
    call _exit

printdigit:
    mov eax, 0x30
    add [num], eax
    mov ecx, num
    mov edx, 1 ;length
    mov ebx, 1 ;write to stdout
    mov eax, 4 ;write call number
    int 0x80
    ret

printn:
    mov eax, 0x0a
    push eax
    mov eax, 4
    mov ebx, 1
    mov ecx, esp
    mov edx, 1
    int 0x80
    add esp, 4
    ret

_exit:
    mov eax, 1
    mov ebx, 0
    int 0x80


section .data
    num dd 3
    array dw 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

mov eax, num

eax = address of num, my debugger shows value 00402000.

mov ebx, [array+8]

ebx = 00050004.

cmp eax,ebx

eax >= ebx so code jumps to skip label.

Write function prints 0x0A which is new line code. If You change to 0x35 You will see 5.

printdigit code is never executed.