I need help with encryption, spaces are giving me a hard time. More details in the body of post

yes I've been bugging the threads with my questions a lot but hopefully this should be the last time. so my goal is to turn a message into numbers, then turn the encoded message (that are now numbers) back into letters again.

here is the code that I've used to get the letters into numbers:

clc, clear
message= 'hello how are you'

s_s = message;
index = 0;
encryption = zeros(1,length(s_s));
for s_ss = 1: length(s_s)
  index = index + 1;
  encryption(index) = (double(s_s(index)) - 96 )

end

and here is the code to switch the numbers back into vectors:

C = 'abcdefghijklmnopqrstuvwxyz1234567890 ';
V = input('enter message here');
v=V;
x=C(v)

I have them separate as for now. The problem however is in the first code, it makes spaces equal to -64. That will not work with the second code to turn it back into letters. I have to keep basic substitution such as a=1 b=2 ect ect and that first code does that but its the spaces that are giving me the problem. Any help would be very appreciated.

This is for an online class, the criteria will be attached.

Answer 1

[Walter Roberson]

' ' does not have a char() of at least 96, so when you subtract 96 you get a negative value.

[James DiNinno]

where and how would I use the char() command in that string?

and thank you!

[Walter Roberson]

space_code = ' ' + 0
space = char(space_code)