How to do Randi with letters

Is it possible to do the RANDI function with letters?

And you will see an example like this:

X7S7-6S6A-Y555-U75T

for i=1:4
     r(i)= randi([1000,9999],1,1);
end
r= num2str(r);
fprintf('Your code is -"%s"',r)

the print look like : Your code is -"4818 3432 2773 8395"

tnx :)

Answer 1

[Jan]

Provide a pool with valid characters and use randi() to determine the random indices:

Pool = ['A':'Z', '0':'9'];
Key  = Pool(randi(numel(Pool), 1, 16));
KeyC = cellstr(reshape(Key, 4, []).');
KeyS = strjoin(KeyC, '-');
fprintf('Your code is: %s', KeyS)

Your code is: MOFK-PDFC-SPEA-4F80

% Or after creation of [Key]:
KeyS = sprintf('%c%c%c%c-%c%c%c%c-%c%c%c%c-%c%c%c%c', Key);  % ugly

[Shahar ben ezra]

Thank you very much!

Answer 2

[Steven Lord]

There's no need for the first loop since randi can create a vector of values.

r = randi([1000,9999],1,4)

r = 1×4

6622 6127 8429 7519

Since you're using a release that includes string I'd use that.

S = string(r)

S = 1×4 string array
    "6622"    "6127"    "8429"    "7519"

Now you can join the strings in S together.

code = "Your code is - " + join(S, " ")

code = "Your code is - 6622 6127 8429 7519"

There are other ways you can "do randi with letters" particularly for your first example where you wanted something like "X7S7-6S6A-Y555-U75T"

allowedChars = ['A':'Z' '0':'9'];
whichChars = randi(numel(allowedChars), [4 4]);
selectedChars = allowedChars(whichChars)

selectedChars = 4×4 char array
    'XA3C'
    'WCML'
    'IS22'
    'J248'

Now turn each of those vectors into strings and join them as before.

code = "Your code is - " + join(string(selectedChars), " : ")

code = "Your code is - XA3C : WCML : IS22 : J248"

[Shahar ben ezra]

Thank you very much!