Preventing input errors from quitting script using while loop

I'm writing a script that includes a prompt for the user to input either '1' or '0' and will record the response in an output txt file.

I want to limit the available responses to 1 and 0, and also prevent throwing an error and stopping the script if the user inputs a '-' or '`' by accident (which are next to the 0 and 1 keys).

Here's an example of I've got for now:

for k = 1:4
prompt2 = ('If CORRECT press 1, if INCORRECT press 0, then press return to advance: ');
    
%---Need to prevent recording non 1's and 0's
%---Need to prevent errors forcing quit (ONLY CATCHES ONCE?)

    try 
    x_or_o = input(prompt2);
           
        while ~isscalar(x_or_o) || (x_or_o ~= 1 && x_or_o ~= 0)
              fprintf('\t***PLEASE PRESS 1 or 0 ONLY***\n');
              prompt2 = ('If CORRECT press 1, if INCORRECT press 0, then press return to advance: ');
              x_or_o = input(prompt2);
        end
    catch
    warning('***PLEASE PRESS 1 or 0 ONLY***');
    x_or_o = 2;
        while ~isscalar(x_or_o) || (x_or_o ~= 1 && x_or_o ~= 0)
              fprintf('\t***PLEASE PRESS 1 or 0 ONLY***\n');
              prompt2 = ('If CORRECT press 1, if INCORRECT press 0, then press return to advance: ');
              x_or_o = input(prompt2);
        end
    end     
    fprintf('Good job! Trial number %d finished!\n',k);
end

This mostly does what I want it to EXCEPT that it can't handle two consecutive errors, only one. Two consecutive inputs of '-' for example will make it quit.

I've tried a few different combinations of loops but I can't seem to get anything to handle errors how I want it to.

Any help would be greatly appreciated!

------------

Edit for clarity:

I'm trying to avoid a situation where a user enters a character that throws an error and exits the program. Instead, I want the user to be re-prompted to enter either 1 or 0 only no matter the number of incorrect inputs. Some specific examples using the above code might help me explain better.

Scenario 1: User only ever inputs 1's and 0's. Here's the command window output:

• >> input_error_handling
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 1 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 0
• Good job! Trial number 2 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 3 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 0
• Good job! Trial number 4 finished!
• >>

Scenario 2: User accidentally hits wrong key but not one that will throw an error:

• >> input_error_handling
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 0
• Good job! Trial number 1 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 2 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 2
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 3
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 9
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 3 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 4 finished!
• >>

Scenario 3: User accidentally hits key that would throw error, but it's caught and their next input is correct:

• >> input_error_handling
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 1 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: `
• Warning: ***PLEASE PRESS 1 or 0 ONLY***
• > In input_error_handling (line 15)
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 2 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: =
• Warning: ***PLEASE PRESS 1 or 0 ONLY***
• > In input_error_handling (line 15)
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 9
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 0
• Good job! Trial number 3 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 0
• Good job! Trial number 4 finished!
• >>

Scenario 4: The user accidentally inputs two error-throwing inputs in a row. This is the situation that the current code can't handle, and when the second error-throwing input is entered the script quits without finishing:

• >> input_error_handling
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 1 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: `
• Warning: ***PLEASE PRESS 1 or 0 ONLY***
• > In input_error_handling (line 15)
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: `
• Error using input_error_handling (line 20)
• Error: Invalid text character. Check for unsupported symbol, invisible character, or pasting of non-ASCII characters.
• >>

Scenarios 1-3 can all be handled, it's just scenario 4 that's the problem. I'd like to find a solution to that, even if it's a relatively unlikely scenario.

Answer 1

[madhan ravi]

for k = 1:4
prompt2 = 'If CORRECT press 1, if INCORRECT press 0, then press return to advance: '
input(prompt2)
end

Gives error when input is '-' :

prompt2 =

    'If CORRECT press 1, if INCORRECT press 0, then press return to advance: '

If CORRECT press 1, if INCORRECT press 0, then press return to advance: -
Error using COMMUNITY (line 3)
Error: Invalid expression. Check for missing or extra characters.

Note: input accepts only number if 's' is not mentioned (lookup doc).

[Lincoln Dunn]

Thank you for your response. However, let me try to explain what I'm looking for a bit more clearly.

I'm trying to avoid a situation where a user enters a character that throws an error and exits the program. Instead, I want the user to be re-prompted to enter either 1 or 0 only no matter the number of incorrect inputs. Some specific examples using the above code might help me explain better.

Scenario 1: User only ever inputs 1's and 0's. Here's the command window output:

• >> input_error_handling
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 1 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 0
• Good job! Trial number 2 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 3 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 0
• Good job! Trial number 4 finished!
• >>

Scenario 2: User accidentally hits wrong key but not one that will throw an error:

• >> input_error_handling
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 0
• Good job! Trial number 1 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 2 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 2
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 3
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 9
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 3 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 4 finished!
• >>

Scenario 3: User accidentally hits key that would throw error, but it's caught and their next input is correct:

• >> input_error_handling
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 1 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: `
• Warning: ***PLEASE PRESS 1 or 0 ONLY***
• > In input_error_handling (line 15)
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 2 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: =
• Warning: ***PLEASE PRESS 1 or 0 ONLY***
• > In input_error_handling (line 15)
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 9
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 0
• Good job! Trial number 3 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 0
• Good job! Trial number 4 finished!
• >>

Scenario 4: The user accidentally inputs two error-throwing inputs in a row. This is the situation that the current code can't handle, and when the second error-throwing input is entered the script quits without finishing:

• >> input_error_handling
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: 1
• Good job! Trial number 1 finished!
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: `
• Warning: ***PLEASE PRESS 1 or 0 ONLY***
• > In input_error_handling (line 15)
• ***PLEASE PRESS 1 or 0 ONLY***
• If CORRECT press 1, if INCORRECT press 0, then press return to advance: `
• Error using input_error_handling (line 20)
• Error: Invalid text character. Check for unsupported symbol, invisible character, or pasting of non-ASCII characters.
• >>

Scenarios 1-3 can all be handled, it's just scenario 4 that's the problem. I'd like to find a solution to that, even if it's a relatively unlikely scenario.