Judging input word based on first letter

How would I write an m-file that asks a user to input a word and only returns a correct response if the word begins with "A","B","C".

x=input('Please input a single word surrounded by parentheses.')
case(first letter begins with A,B,C)
         disp(Input word is correct.)
case(first letter does not begin with A,B,C)
         disp(Input is incorrect. Please input a correct word.)
end

thanks!

Answer 1

[Walter Roberson]

Use the 's' option of input(). Subscript to get the first letter. switch() with case {'A', 'B', 'C'}

Question: what about 'a', 'b', 'c' ?

Watch out for the user pressing return without entering a word