How to show a string 10 times using while loop in assembly language?

Question

How to show string 10 times in assembly language?

Here is my code:

.model small
 .stack 100h
 .data
    msg db 'rashed   $'
 .code
 
 main proc
    
     
    mov ax,@data
    mov ds,ax
    
    lea dx,msg
    mov ah,9      ;string output
     int 21h 
    
       
      mov dx,0   ;dx counts characters
      mov ah,9   ;prepare for read
      int 21h  
      
      
       
     
      
     while_:
      cmp al,0dh     ;carriage return?
      je end_while    ;yes exit
      inc dx           ;no carriage return, increment count
      int 21h          ;read character
      jmp while_       ;loop back
      end_while:  
    exit:
    mov ah,4ch
    int 21h
    main endp
 end main

output is:

I want to show this string 10 times but the string subtracts? How to show that 10 times?

Answer 1

mov dx,0   ;dx counts characters

To show the same text a number of times, choose a counter register different from the registers that are required to perform the output (In your case AX and DX). I suggest putting the counter in CX.

    mov  cx, 11
while_:
    dec  cx           ;Change counter
    jz   end_while    ;Exit after 10 iterations
    mov  ah, 9
    int  21h          ;Print string
    jmp while_        ;Loop back
end_while:

Because a while-loop tests the condition first, I assigned 11 instead of 10.