Question

一道汇编语言的题目。。求高手来解答

在内存数据段存储器中，从ADDR单元开始存有一个字符串，它以“$”符号作为结束标志，试编写程序统计该字符串的长度（$字符不计入长度），并把长度值存入LETH字单元。

Answer 1

统计字符串并显示。

;----------------------------------------
;统计字符串的长度(最多能统计255个字符)
data SEGMENT
str DB 'I love you forever$'
data ENDS
;----------------------------------------
code SEGMENT
assume CS:code, DS:data
start:
MOV AX, data
MOV DS, AX
SUB AX, AX
LEA SI, str

compar:
MOV BL, [SI]
CMP BL, '$'
JZ binidec
INC AL
INC SI
JMP compar

binidec:
MOV BL, AL
MOV CL, 10d
CALL div_dec
MOV CL, 1d
CALL div_dec
MOV AH,4ch
INT 21h
;----------------------------------------
div_dec PROC near

MOV AL, BL
CBW
DIV CL
MOV BL, AH
MOV DL, AL
ADD DL, 30h
MOV AH, 02h
INT 21h
RET
div_dec ENDP
;----------------------------------------
code ENDS
END start
;----------------------------------------

Answer 2

data segment
addr db 'bdfjdhjfhefkek....','$'
leth dw 0
data ends

code segment
main proc far
assume cs:code,ds:data

start:

MOV AX,DATA
MOV DS,AX
MOV BX,OFFSET ADDR

MOV CX,0
NEXT:
MOV AL,[BX]
CMP AL,'$'
JE END_A
INC CX
INC BX
JMP NEXT

END_A:
MOV BX,OFFSET LETH
MOV [BX],CX
RET

main endp
code ends
end start