%uppercase(string) -> string
%Description:
%  Takes in a string and returns an uppercase version of the string
%Examples:
%  uppercase('red') -> 'RED'
%  uppercase('cyan') -> 'CYAN'
%  uppercase('GREEN') -> 'GREEN'
%  uppercase('blUE') -> 'BLUE'
function out=uppercase(stringValue)
out = char(zeros(1, length(stringValue)));
for letter=[1:length(stringValue)]
    if (double(stringValue(letter)) >= 97 && double(stringValue(letter)) <= 122)
        %make uppercase
        out(letter) = char(double(stringValue(letter)) - 32);
    else
        out(letter) = stringValue(letter);
    end
end