cmpstr.txt

汇编语言

data segment
  string1 db 50,0,50 dug(?)
  string2 db 50,0,50 dup(?)
  mess1 db 'please enter the first string:','$'
  mess2 db 'please enter the second string:','$'
  mess3 db 'The first is less than the second.',13,10,'$'
  mess4 db 'The first is bigger than the second.',13,10,'$'
  mess5 db 'They are equal',13,10,'$'
data ends
code segment
  assume cs:code,ds:data,es:data
start:
push ds
xor ax,ax     ;ax清零
mov ax,data
mov ds,ax
mov es,ax     ;初始化

;输入第一个字符串
mov ax,data
mov ds,ax
mov dx,offset mess1
mov ah,09h
int 21h       ;输出please enter the first string:
mov ax,data
mov ds,ax
mov dx,offset string1
mov ah,0ah
int 21h
call crlf

;输入第二个字符串
mov ax,data
mov ds,ax
mov dx,offset mess2
mov ah,09h
int 21h       ;输出please enter the second string:
mov ax,data
mov ds,ax
mov dx,offset string2
mov ah,0ah
int 21h
call crlf

   lea si,string1
   lea di,string2
   add si,2
   add di,2

;下面是字符串比较
   again:
   mov bl,byte ptr [di]
   cmp [si],bl
   jl Little     ;转到小于输出
   jg greate     ;转到大于输出
   add si,1
   add di,1
   cmp byte ptr [si],0    
   jnz again
   
   
   ;两字符串等于的输出   
call crlf
mov ax,data
mov ds,ax
mov dx,offset mess5
mov ah,09h
int 21h   
mov ah,4ch
int 21h

   ;小于的输出
Little:
call crlf
mov ax,data
mov ds,ax
mov dx,offset mess3
mov ah,09h
int 21h   
mov ah,4ch
int 21h
   
   ;大于的输出
greate:
call crlf
mov ax,data
mov ds,ax
mov dx,offset mess4
mov ah,09h
int 21h
mov ah,4ch
int 21h

;下面这个子程序是用来做 回车换行 用的
crlf proc near
  mov dl,0dh
  mov ah,2
  int 21h
  
  mov dl,0ah
  mov ah,2
  int 21h
  ret
 crlf endp
code ends
end start         ;结束