使用 include 'emu8086.inc' 反轉字符串的大小寫和順序 (Reverse case and order of a String using include 'emu8086.inc')

問題描述

使用 include 'emu8086.inc' 反轉字符串的大小寫和順序 (Reverse case and order of a String using include 'emu8086.inc')

在以下代碼中，我可以反轉字符串，但我不知道如何在此代碼中添加函數以獲得以下結果：

輸入 AbCDeF_XYz 輸出：Zyx_fEdcBa

name "REVERSE"

include "emu8086.inc" 

      print "Enter a string:"
      MOV DX,11
      CALL get_string   
      printn
      MOV DI,0x0

ReadString:

      MOV AL,[ds+di]
      CMP AL,0x0
      JE Reverse
      INC DI
      PUSH AX
      JMP ReadString
Reverse:

      POP AX
      MOV AH,0xE
      INT 0x10
      CMP AL,0x0
      JNE Reverse

HLT

DEFINE_GET_STRING
END

參考解法

方法 1:

I can suggest these 3 solutions for your program:

• In your push loop you should also push the zero because now your pop loop will not correctly find a finishing zero!

    MOV DI,0x0
  ReadString:
    MOV AL,[ds+di]
    INC DI
    PUSH AX
    cmp al, 0
    jne ReadString
  Reverse:
  

• You can tackle the case swap by looking closely at the input string. It only has the underscore character _ that poses a problem. You'll have to test for it and then bypass the case swap:

    MOV DI,0x0
  ReadString:
    MOV AL,[ds+di]
    INC DI
    cmp al,"_"
    je  NoSwap
    xor al,32  ;This toggles lowercase and uppercase
  NoSwap:
    PUSH AX
    cmp al, 0
    jne ReadString
  Reverse:
  

• In your current program you print the terminating zero. This is almost certainly not what you should do!

  Reverse:
    POP AX
    cmp al,0
    je  EndOfReverse
    MOV AH,0xE
    INT 0x10
    Jmp Reverse
  EndOfReverse:
    HLT
  

(by BhhooHD、Fifoernik)

參考文件

1. Reverse case and order of a String using include 'emu8086.inc' (CC BY‑SA 2.5/3.0/4.0)