Print one string from arrays of strings

Question

How to make arrays of string in assembler and work with them?

I try:

arrayOfWords BYTE "BICYCLE", "CANOE", "SCATEBOARD", "OFFSIDE", "TENNIS"

and after I want to print second word, but its dont work

    mov edx, offset arrayOfWords[2]
    call WriteString

but He print me all world.

Answer 1

arrayOfWords is not an array, not even a variable. It's just a label that tells the assembler where it can find something, in this case a bunch of characters. Irvine's WriteString expects a null-terminated bunch of characters as string. There are two methods to treat that bunch of characters as string array.

1. Search the memory for the right address to the desired string. At every null begins a new string.

   INCLUDE Irvine32.inc
   
   .DATA
   manyWords BYTE "BICYCLE", 0
       BYTE "CANOE", 0
       BYTE "SCATEBOARD", 0
       BYTE "OFFSIDE", 0
       BYTE "TENNIS", 0
       BYTE 0                              ; End of list
   len equ $ - manyWords
   
   .CODE
   main PROC
   
       mov edx, 2                          ; Index
       call find_str                       ; Returns EDI = pointer to string
   
       mov edx, edi
       call WriteString                    ; Irvine32: Write astring pointed to by EDX
   
       exit                                ; Irvine32: ExitProcess
   main ENDP
   
   find_str PROC                           ; ARG: EDX = index
   
       lea edi, manyWords                  ; Address of string list
   
       mov ecx, len                        ; Maximal number of bytes to scan
       xor al, al                          ; Scan for 0
   
       @@:
       sub edx, 1
       jc done                             ; No index left to scan = string found
       repne scasb                         ; Scan for AL
       jmp @B                              ; Next string
   
       done:
       ret
   find_str ENDP                           ; RESULT: EDI pointer to string[edx]
   
   END main
   

2. Build an array of pointers to the strings:

   INCLUDE Irvine32.inc
   
   .DATA
   wrd0 BYTE "BICYCLE", 0
   wrd1 BYTE "CANOE", 0
   wrd2 BYTE "SCATEBOARD", 0
   wrd3 BYTE "OFFSIDE", 0
   wrd4 BYTE "TENNIS", 0
   
   pointers DWORD OFFSET wrd0, OFFSET wrd1, OFFSET wrd2, OFFSET wrd3, OFFSET wrd4
   
   .CODE
   main PROC
   
       mov ecx, 2                          ; Index
       lea edx, [pointers + ecx * 4]       ; Address of pointers[index]
       mov edx, [edx]                      ; Address of string
       call WriteString
   
       exit                                ; Irvine32: ExitProcess
   main ENDP
   
   END main
   

BTW: As in other languages, the index starts at 0. The second string would be index = 1, the third index = 2.