Assembly Program to Count Characters in a String

The program will prompt the user to input a string and will count the number of characters present in that string. The program will not count white spaces as white spaces are not characters.

The program takes a string and stores the string in STRING and will start iteration if there is a white space the program will continue without incrementing CHARACTERS and if there is a character the program will increment CHARACTERS. After counting the characters the program simply prints the number of characters.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

.MODEL SMALL .STACK 100H .DATA STRING DB 100 DUP(?) MSG1 DB "ENTER A STRING: $" MSG2 DB 0DH, 0AH, "NO. OF CHARACTERS: $" CHARACTERS DW 0 .CODE MAIN PROC MOV AX, @DATA MOV DS, AX MOV ES, AX MOV AH, 9 LEA DX, MSG1 INT 21H LEA DI, STRING MOV AH, 1 READ: INT 21H CMP AL, 0DH JE ENDOFSTRING STOSB JMP READ ENDOFSTRING: MOV AL, "$" STOSB XOR BX, BX COUNT: CMP [STRING+BX], '$' JE EXIT CMP [STRING+BX], ' ' JE SPACE INC BX INC CHARACTERS JMP COUNT SPACE: INC BX JMP COUNT EXIT: MOV AH, 9 LEA DX, MSG2 INT 21H MOV AH, 2 MOV DX, CHARACTERS ADD DX, 30H INT 21H MAIN ENDP END MAIN

Output: