Infinite Loop Of Switch

Hi, Matlab Community

Iam just curious about this. Could matlab do an infinite loop by using switch and case, to be exact when the input parameter is not same as the desire input?

Iam typing an example code like this :

%Case 1
a1 = [2, 1; 1, 3]; 
inverse_a1 = inv(a1); 

%Case 2
a2 = [2, -4; -3, 6];  
inverse_a2 = inv(a2); 

%Case 3
a3 = [2.01, 1.5; 4, 3]; 
inverse_a3 = inv(a3); 

in = input('Enter the number of case (1, 2, or 3) = ');
switch input('Type the case number (1, 2, or 3) = ')
    case 1
        
        out1 = sprintf("Matrix inversion from case 1 is");
        disp(out1);
        disp(inverse_a1)
    case 2
        
        out2 = sprintf("Matrix inversion from case 2 is");
        disp(out2);
        disp(inverse_a2)
    case 3
       
        out3 = sprintf("Matrix inversion from case 3 is");
        disp(out3);
        disp(inverse_a3)
        
    otherwise
        
            disp(in); %I want to create this otherwise statement to be Infinite Loop of asking to the user
            %instead of 1 only.
        
        end

By using the above code, if the input is not 1, 2, or 3, it will deliver us directly to the otherwise statement that occurs only 1 times and then make us out from Switch region (end the switch). Could it possible to create an infinite loop so then we will continuously meet the variable of " in " ( input('Enter the number of case (1, 2, or 3) = '); ) again and again?

Thank you very much..... /.\ /.\ /.\

Answer 1

[Cris LaPierre]

Switch statements do not loop, so no, it is not possible to create an infinite loop using one.

If you want to create a loop, consider incorporating a while loop into your code.

in = 0;
% While loop repeats until in is 1,2 or 3
while ~ismember(in,1:3)
    in = input('Enter the number of case (1, 2, or 3) = ');
end

% Only reaches switch statement if in is 1, 2 or 3
switch in
    case 1      
        out1 = sprintf("Matrix inversion from case 1 is");
        disp(out1);
        disp(inverse_a1)
    case 2
        out2 = sprintf("Matrix inversion from case 2 is");
        disp(out2);
        disp(inverse_a2)
    case 3       
        out3 = sprintf("Matrix inversion from case 3 is");
        disp(out3);
        disp(inverse_a3)
end

Answer 2

[Image Analyst]

No, you'll never have an infinite loop with a switch statement because there is no looping at all. It just goes straight through. If you want one, you'll have to put it inside a while statement:

while true
    in = input('Enter the number of case (1, 2, or 3) = ');
    switch in
        case 1 % etc.
        otherwise
    end
end % of while.  Use control-c to break out