How to deal with hexadecimal values

hi:wave:
i write a programe to convert the ascii to hexadecimal then i want to write a function to deal with these hexadecimal value>>>> for better explain here is an exapmle:
if i have these hexadecimal value 44 2A 66 E2 F6 77
so i want to write a function that look to first character (44) to see what the values around it (before it and after it) and replace it is value depend on that such that replace the (44) with another value like (54) and then go to the next value(2A) and see the values before and the value after >>>>>
which mean for example if it is found that the value before the value (2A) is (44) and the value after it is (66) replace it with (77) and if it found that the value before it is (E2) and the value after is (66) replace it with (F3) and so on.....
and second problem how to make the function to see the the values as two bit not bit by bit which mean to look to the value 44 and then to 2A and so on not to look to each bit (see 4 then 4 then 2 then A)
i hope you understand the idea
and sorry for my english:blush:

any idea to do that???

Quote:

---

Originally Posted by king4ever101

hi:wave:
i write a programe to convert the ascii to hexadecimal then i want to write a function to deal with these hexadecimal value>>>> for better explain here is an exapmle:
if i have these hexadecimal value 44 2A 66 E2 F6 77
so i want to write a function that look to first character (44) to see what the values around it (before it and after it) and replace it is value depend on that such that replace the (44) with another value like (54) and then go to the next value(2A) and see the values before and the value after >>>>>
which mean for example if it is found that the value before the value (2A) is (44) and the value after it is (66) replace it with (77) and if it found that the value before it is (E2) and the value after is (66) replace it with (F3) and so on.....

---

So you have a string and convert each character to its hex ascii value, in 44 2A 66 E2 F6 77 the spaces separate the characters, right?
You menttion a second problem, but what is exactly the first problem?

there is no spaces separate the characters it is on the form 442A66E277
and the first problem what's the function we use to see the character before and the character after each character....
and the second how to see each 2 bits as one character as to see the two bits 4 & 4 as one character 44 and so on 2A 66...........
thx for reply

Quote:

---

Originally Posted by king4ever101

there is no spaces separate the characters it is on the form 442A66E277
and the first problem what's the function we use to see the character before and the character after each character....
and the second how to see each 2 bits as one character as to see the two bits 4 & 4 as one character 44 and so on 2A 66...........
thx for reply

---

OK no spaces then, but I assume every 2 digits represent a character? And when you say "...how to see each 2 bits as one character..." don't you mean bytes instead of bits?

Quote:

---

Originally Posted by krtxmrtz

but I assume every 2 digits represent a character? And when you say "...how to see each 2 bits as one character..." don't you mean bytes instead of bits?

---

yes every 2 digits represent a character but how to make the function see that evry 2 digits represent a character (how make the function know that we deal with hex values not a asscii values an so deal with 2 digits at a time )

See if this is any use to you (haven't tested it, though). It takes a string that has been assigned 442A66E277 and splits it in an array of 2 characters.

Code:

---

Dim i As Integer
Dim str As String
Dim chr2() As String*2
'
str = "442A66E277"
i = 0
While str<>""
  ReDim Preserve chr2(i)
  chr2(i) = Left(str, 2)
  str = Mid(str, 3)
  i = i + 1
Wend

---

Quote:

---

Originally Posted by king4ever101

hi:wave:
i write a programe to convert the ascii to hexadecimal then i want to write a function to deal with these hexadecimal value>>>> for better explain here is an exapmle:
if i have these hexadecimal value 44 2A 66 E2 F6 77
so i want to write a function that look to first character (44) to see what the values around it (before it and after it) and replace it is value depend on that such that replace the (44) with another value like (54) and then go to the next value(2A) and see the values before and the value after >>>>>
which mean for example if it is found that the value before the value (2A) is (44) and the value after it is (66) replace it with (77) and if it found that the value before it is (E2) and the value after is (66) replace it with (F3) and so on.....
and second problem how to make the function to see the the values as two bit not bit by bit which mean to look to the value 44 and then to 2A and so on not to look to each bit (see 4 then 4 then 2 then A)
i hope you understand the idea
and sorry for my english:blush:

---

Why the added complication? Why not just manipulate the original ascii values rather than working with its hex representation (the relationship ascii-hex is one-is-to-one anyway). That gives you the advantage of bit comparisons without the overhead of string manipulation.

Quote:

---

Originally Posted by leinad31

Why the added complication? Why not just manipulate the original ascii values rather than working with its hex representation (the relationship ascii-hex is one-is-to-one anyway). That gives you the advantage of bit comparisons without the overhead of string manipulation.

---

yes man you are right but i write a programe to send data to receiver (channel list in arabic) so the receiver has his own table that give to each character an hex value so as you know in arabic the characters are connectind to gather so each character has 3 or 4 form depend on his position in the word (in the begining of the word and in the middle and in the last) not like english has 1 shape to the character in any palce in the word...so the reciver give to each character many hex values depend in his position in the word while in computer give to each arabic character one hex value how ever it is position is, and use logical operations to view it in the right shape ...so when i send to receiver this data it is look like separate characters not connecting characters because the receiver do not use logical operations to determe the shape of the character how should it appear like computer
so i try to write this programe that take the data and convert it to hex and then take each character to see it is position (what the character before and character after it) then change it is value depend on this way.....
for example ( 44 25 A4) it take the 44 and see there is no character before it or there is space befor it and after it the value 25 so it change it is value to 72 (which represent to a character in the biginnig of the word) and so on........

mr. krtxmrtz
i will try it:thumb:

I wasn't discussing the actual processing which I had no idea about. I was pointing out the use of strings and concept of byte manipulation.

Code:

---

Option Explicit

Private Sub Form_Load()
Dim strArr() As Byte
Dim i As Long

  strArr = "Hello World"
  For i = 0 To UBound(strArr) - 1
      Debug.Print Hex(strArr(i)) & ", " & Chr(strArr(i)) & ", shifted " & IIf(i<250, Chr(i+5), Chr(i-250))
  Next
End Sub

---

Now isn't the array easier to work with than your string?

The text is represented properly as Unicode characters, so why not just send the Unicode string?

Quote:

---

Originally Posted by Al42

The text is represented properly as Unicode characters, so why not just send the Unicode string?

---

the reveiver do not understand Unicode string when i send it it is apeear like ????????? ?? ?????