Add code to have switch repeat if a case is not met

fprintf('Difficulty level: \nEasy: [0, 10] \nMedium: [0, 50] \nHard: [0, 100] \n'); % Print statement outputting different difficulties
diff_level = input('Choose difficulty level: ', 's');   % user input for which difficulty desired, 's' is present since input is string
numplayer = input('How many players: '); % user input for number of players

leaderboard = cell(numplayer,2);         % Stores result of guesses

switch diff_level                      % Switch case to assign difficulties with ranges
    case 'Easy'
        max_number = 10;
    case'easy' 
        max_number = 10;
    case'EASY'
        max_number = 10;
    case 'Medium'
        max_number = 50;
    case'medium'
        max_number = 50;
    case'MEDIUM'
        max_number = 50;
    case 'Hard'
        max_number = 100;
    case'hard'
        max_number = 100;
    case'HARD'
        max_number = 100;
    otherwise
        disp('Difficulty not available.')
end

for player = 1:numplayer
    
    number_of_attempt = 1;
    rng('shuffle')                               % Random number generator seeded to time
    number_to_guess = randi([0, max_number]);     % Creates random # from 0 to max number set by difficulty

    
    fprintf('\nPlayer Ready\n')
    player_guess = input('Take a guess: ');
    
    while player_guess ~= number_to_guess        % While loop to run untill correct # is guessed
        if player_guess < number_to_guess        % if statement for low guess
            disp('Too low! guess again:')
        end
        if player_guess > number_to_guess        % If statement for high guess
            disp('Too high! guess again:')
        end
        number_of_attempt = number_of_attempt + 1;
        player_guess = input('Take a guess: ');
    end
    
    leaderboard{player, 1} = number_of_attempt;                 % adds # of guesses to leaderboard
    leaderboard{player, 2} = input('Enter player name: ', 's'); % assigns name to that persons attempt
    
    
end
leaderboard = sortrows(leaderboard,1);      % sort the table
position = 0;
fprintf('-----------------------------RESULTS--------------------------------\n')
for player = 1:numplayer
   position = player;
   if player > 1                            % reduce position for draw
      if leaderboard{player, 1} == leaderboard{player-1, 1}       % Orders playes by guesses
           position = position - 1;
      end
   end
   fprintf('%d place %s with %d attempts. \n', position, leaderboard{player,2}, leaderboard{player,1}) % print statement to output order of players
    
end

When a case isnt met the code ends and has an error. How can I instead have the code continue to run and repeat the switch if a case isn't met?

Answer 1

[Steven Lord]

You can simplify your switch call so you don't have to include 2^(number of letters) cases each with a different combination of cases. The lower function converts text into all lower case.

E = 'EaSY';
switch lower(E)
    case 'easy'
        disp('Easy case selected')
    case 'medium'
        disp('Medium case selected')
    otherwise
        disp('No match')
end

Easy case selected

What happens if I remove the lower call?

E = 'EaSY';
switch E
    case 'easy'
        disp('Easy case selected')
    case 'medium'
        disp('Medium case selected')
    otherwise
        disp('No match')
end

No match

I'd probably assign max_number some easily detected "invalid" value and wrap your switch call in a while loop that tests if max_number is still in that invalid state.

N = NaN;
while isnan(N)
    x = randi(10); % Random integer between 1 and 10
    fprintf("Generated %d.\n", x)
    if x >= 9
        N = x; % Break out of the loop as soon as 9 or 10 is generated
    end
end

Generated 7.
Generated 1.
Generated 7.
Generated 9.

disp(N)

     9

While I used randi to generate the data that decides whether or not to exit the while loop you could call input and switch.

Answer 2

[Jan]

knownLevels = {'easy', 'medium', 'hard'};
Levels      = [10, 50, 100];
fprintf('\nChoose one of the known levels: %s\n', strjoin(knownLevels, ', '));
max_number = 0;
while max_number == 0
   diff_level = input('Choose difficulty level: ', 's');
   match      = strcmpi(diff_level, knownLevels);
   if any(match)
      max_number = Levels(match);
   else
      fprintf('\nChoose one of the known levels: %s\n', strjoin(knownLevels));
   end
end

Answer 3

[Eric Sofen]

A while loop is one way to accomplish this. Also note that you can use lower() to reduce the number of cases.

max_number = nan;

while isnan(max_number)
    fprintf('Difficulty level: \nEasy: [0, 10] \nMedium: [0, 50] \nHard: [0, 100] \n'); % Print statement outputting different difficulties
    diff_level = input('Choose difficulty level: ', 's');   % user input for which difficulty desired, 's' is present since input is string
    numplayer = input('How many players: '); % user input for number of players

    switch lower(diff_level) % Switch case to assign difficulties with ranges
        case'easy' 
            max_number = 10;
        case'medium'
            max_number = 50;
        case'hard'
            max_number = 100;
        otherwise
            disp('Difficulty not available. Please specify game parameters again')
            % don't set max_number
    end
end

% ...