Use Do While Loop in Assembly.

org 100h

.model small

.stack 100h

.data

  c db ?

  value db '0';

  red db "Red$"

  green db "Green$"

  blue db "Blue$"

  w db 0ah,0dh,"Wrong Choice$"

  nl db 0ah,0dh,"$"

 

.code

 main proc

   

   mov dx,@data

   mov ds,dx

 

;this code will behave like do while loop

level:

  ;c=getchar();

   mov ah,7

   int 21h

   mov c,al

 

   ;if(c=='r') printf("Red")

 

   cmp c,'r'     ;if

   je printredR

 

   cmp c,'g'

   je printredG  ;else if

 

   cmp c,'b'

   je printredB  ;else if

   jmp wrong     ;else

 

 

 ;blocks

 printredR:

            lea dx,red

            add value,1

            mov ah,9

            int 21h

            jmp exit

           

 printredG:

            lea dx,green

            add value,1

            mov ah,9

            int 21h

            jmp exit

 printredB:

            lea dx,blue

            add value,1

            mov ah,9

            int 21h

            jmp exit

           

 wrong:

        lea dx,w

        mov ah,9

        int 21h

       

        mov ah,9

        lea dx,nl

        int 21h

       

        cmp value,'2'

        jmp level    

           

 exit:

     

        mov ah,4ch

        int 21h

       

 endp

 end main