ASSUME CS:CODES
CODES SEGMENT
START:
mov ah,0
int 16h
cmp al,0dh ;如果输入的是enter键退出
je over
cmp al,’1’ ;在1-9之间,则显示其值,之后等待新字符输入
jb next1
cmp al,’9’
ja next1
mov dl,al
mov ah,2
int 21h
jmp start
next1: ;在a-z后A-Z之间,则输出’c’,之后等待新字符输入
cmp al,’A’
jb next2
cmp al,’Z’
ja next2
jmp outp
next2:
cmp al,’a’
jb start ;否则不做处理,等待重新输入
cmp al,’z’
ja start
outp:
mov dl,’c’
mov ah,2
int 21h
jmp start
over:
MOV AH,4CH
INT 21H
CODES ENDS
END START
选择判断程序
运行结果如图所示: