Remove Element in Array [ASSEMBLY] [duplicate] - arrays

Question

I have input like this:
This is, ,,, *&% a ::; demo + String. +Need to**#!/// format:::::!!! this.`
Output Required:
ThisisademoStringNeedtoformatthis
I have to do this without using str_trim.
Edit: I am writing an encryption program. I have to remove all punctuation from the string and turn all lower case letters to uppercase before I encrypt it.
I added the code. I need to remove the spaces, or any punctuation before I turn it to upper case. So far I haven't found anything in my book that could help with this except str_trim which we aren't allowed to use.
INCLUDE Irvine32.inc
.data
source byte "This is the source string",0
.code
main proc
mov esi,0 ; index register
mov ecx,SIZEOF source ; loop counter
L1:
mov al,source[esi] ; get a character from source
and source[esi], 11011111b ; convert lower case to upper case
inc esi ; move to next character
loop L1 ; repeat for entire string
mov edx, OFFSET source
call WriteString
exit
main endp
end main

Answer 1

Your are already trying to change from lowercase to uppercase, so, I will give you a hand to remove the punctuation. Next code uses my suggestion : moving the uppercase letters to an auxiliary string ignoring the punctuation characters. I used EMU8086 compiler :
.stack 100h
.data
source db "STRING, WITH. PUNCTUATION : AND * SPACES!$"
aux db " "
.code
mov ax, #data
mov ds, ax
;REMOVE EVERYTHING BUT UPPERCASE LETTERS.
mov si, offset source ; POINT TO STRING.
mov di, offset aux ; POINT TO AUXILIARY.
L1:
mov al, [ si ] ; get character from source
;CHECK IF END STRING ($).
cmp al, '$'
je finale
;CHECK IF CHAR IS UPPERCASE LETTER.
cmp al, 65
jb is_not_a_letter ; CHAR IS LOWER THAN 'A'.
cmp al, 90
ja is_not_a_letter ; CHAR IS HIGHER THAN 'Z'.
;COPY LETTER TO AUX STRING.
mov [ di ], al
inc di ; POSITION FOR NEXT CHARACTER.
is_not_a_letter:
inc si ; move to next character
jmp L1
finale:
mov [ di ], al ; '$', NECESSARY TO PRINT.
;PRINT STRING.
mov dx, OFFSET aux
mov ah, 9
int 21h
;END PROGRAM.
mov ax, 4c00h
int 21h
I ended the strings with '$' because I print the string with int 21h.
As you can see, I'm not using CX nor the LOOP instruction. What I do is to repeat until '$' is found. You can do the same until 0 is found.

Answer 2

This is my code after removing all the punctuation and turning it to uppercase.
INCLUDE Irvine32.inc
.data
source byte "STriNG, ## WITH.[][][ lalalala PUncTuATION : AND * SpaceS!", 0
target byte SIZEOF source DUP(0), 0
.code
main PROC
pushad
mov edx, offset source
call WriteString
call CrlF
mov edx, 0
mov esi, offset source
mov edi, offset target
L1:
mov al, [ esi ] ; get character from source
cmp al, 0
je final
cmp al, 65
jb not_letter ; if char is lower than 'A' jump to not letter
cmp al, 122
ja not_letter ; if char is greater than 'z' jump to not letter
cmp al, 90
ja Label1 ; jump if above 'Z'
jmp next ; false
Label1:
cmp al, 97
jl Label2 ; jmp if less than 'a'
jmp next ; false
Label2: ; if both are true than is greater than 'Z' but less than 'a'
jmp not_letter ; jump to not letter
next:
mov [ edi ], al
inc di ; position to next character.
not_letter:
inc si ; move to next character
jmp L1
final:
mov [ edi ], al
mov edx, OFFSET target
mov ah, 9
call WriteString
call CrlF
mov esi,0 ; index register
mov ecx,SIZEOF source ; loop counter
L2:
mov al, target[esi] ; get a character from source
and target[esi], 11011111b ; convert lower case to upper case
inc esi ; move to next character
loop L2 ; repeat for entire string
mov edx, OFFSET target
call WriteString
call CrlF
popad
exit
main endp
end main