汇编语言（七）之字符串转大写

输入一串字符，将字符串的小写字母转成大写字母

程序运行：

代码：

datas segment
   originalCaseMaxLength        db 0ffh,0
   originalCase                 db 100h dup(?)
  
   uppercase                    db 100h dup(?)
 
   inputPrompt                  db 'input a line of character:$'
   outputoriginalCasePrompt     db 0dh,0ah,'show noriginal characters:$'
   outputUppercasePrompt        db 0dh,0ah,'turn uppercase characters:$'
datas ends

stacks segment

    db 100h dup(?)

stacks ends

codes segment

assume cs:codes,ds:datas,ss:stacks
main   proc  far
start:
       push ds
	   mov ax,0h
	   push ax
       mov ax,datas           ;初始化ds
	   mov ds,ax

	   lea dx,inputPrompt     ;输出输入提示
	   mov ah,9
	   int 21h
	   
	   lea dx,originalCaseMaxLength
	   mov ah,10 
	   int 21h
	   
       ;输入并且转换小写字母成大写字   
	   mov cl,originalCaseMaxLength+1                         ;记录输入的字符个
	   mov ch,0
	   mov bx,0
	   s:
		  mov al,originalCase[bx]
		  cmp al,'a'                    
		  jae s1                        ;如果al>='a',则跳转s1，判断是否al<='z'
		  jmp s3                        ;否则跳s3，直接保存al于uppercase
		  
		  s1: 
		    cmp al,'z'
		    jbe s2                      ;如果al<='z',则al转大写字
			jmp s3                      ;否则跳s3，直接保存al于uppercase
			
		  s2: 
		    sub al,20h                  ;转大写字母
			
		  s3: 
		    mov uppercase[bx],al        ;保存al于uppercase
			inc bx
			
         loop s
	
	
	break:
		 
		 mov uppercase[bx+1],'$'            ;设置输出字符
		 mov originalCase[bx+1],'$'
		 
		 lea  dx,outputoriginalCasePrompt      ;输出原始字符提示
		 mov ah,9
		 int 21h
		 
         lea  dx,originalCase                  ;输出原始字符
		 mov ah,9
		 int 21h
		 
   		 lea  dx,outputUppercasePrompt      ;输出转换字符串提示
		 mov ah,9
		 int 21h
		 
		 lea  dx,uppercase                  ;输出转换字符
		 mov ah,9
		 int 21h
	    
       
       
       
       ret
	   
main endp
codes ends

end main