Switch Statements for detecting the sign of a number

Hi, I want to detect the sign of a number that I entered with using switch statements

I wote the code there is a problem about returning the results

When I entered -1, the matlab returns: I do not know

Also When I entered 0, the matlab returns: The number is negative

Help me about this problem. This case could be easily done with using for loop but I want this with switch statements.

n=input('Enter a number ');

switch n
    case n<0
        disp('The number is negative')
    case n==0
        disp('The number is 0')
    case n>0
        disp('The number is positive')
        
    otherwise
        disp('I do not know')
end

Answer 1

[Walter Roberson]

switch n case n<0 is effectively

if any(ismember(n, n<0))

n<0 is going to evaluate to either 0 or 1, and that is going to be compared to the number itself. Neither 0 nor 1 are less than 0, so n<0 will always be false (0), and ismember(0,0) is true so you would get a match.

If you must use logical tests in the case (not recommended because that is confusing to most people) then you need to use

    switch true

[Std1]

Thank you very much, I am just learning Matlab and I want to try every functions on a problem. That is why I am using Switch statement.

[DGM]

Alternatively

switch sign(n)
    case -1
        disp('The number is negative')
    case 0
        disp('The number is 0')
    case 1
        disp('The number is positive')
    otherwise
        % this will occur for NaN
        disp('n is not a number')
end

Answer 2

[Mitish]

n=input('enter the number')
switch true
    case n<0
        disp('negative number')
    case n>0
        disp('positive number')
    case n==0
        disp('zero')

    otherwise
        disp('other value')
end