Question

Please write in x86 Assembly language on Visual Studio

Write a program to compare two strings in locations str1 and str2. Initialize str1 to Computer and initialize str2 to Compater. Assume Str1 holds the correct spelling and str2 may have an incorrect spelling. Use string instructions to check if str2 is correct and if not correct the mistake in str2.

Answer 1

INCLUDE io.h
	Cr EQU 0ah
	Lf EQU 0dh
	data SEGMENT
	p_str1 DB Cr, Lf, 'Enter 1st string: ',0
	p_str2 DB Cr, Lf, 'Enter 2nd string: ',0
	p_not1 DB Cr, Lf, 'The strings are not same because of different lengths',0
	p_not2 DB Cr, Lf, 'The strings are not same because of different characters',0
	p_same DB Cr, Lf, 'The strings are the same',0
	str1 DB 100 DUP (?)
	str2 DB 100 DUP (?)
	data ENDS
	code SEGMENT
	ASSUME cs:code, ds:data
	start: mov ax, data
	mov ds, ax
	;input str1
	output p_str1
	inputs str1, 100
	mov bx, cx
	;input str2
	output p_str2
	inputs str2, 100
	;compare lengths
	cmp bx, cx
	jne l_not1;if different length jump
	;initialize
	lea si, str1
	lea di, str2
	;iterate to compare characters
	nxt_chk:mov al, [si];copy the two bytes in ax
	mov ah, [di]
	cmp al, ah;compare the two bytes
	jne l_not2;if not (ah==al)
	inc si;increment the two bytes
	inc di
	dec cx;decrement the count(string length)
	jz l_same;if count=0 the strings are same
	jmp nxt_chk;else jump to ceck next byte
	l_not1: output p_not1
	jmp quit
	l_not2: output p_not2
	jmp quit
	l_same: output p_same
	quit: mov al, 00h
	mov ah, 4ch
	int 21h
	code ENDS
	END start