Let users enter anything, save integers, give warning otherwise

I want to let users enter any text into my application. I am using the disp() command for this.

I want the users to be able to enter anything. If they enter an integer I want to save it as a string or integer. If they enter anything else I want to give them a warning.

This code doesn't work. Can you help me fix it?

userVar = disp('Enter an integer: ') 

if (isinteger(userVar)) 
% e.g. Enter an integer: 3

     A = [A userVar]

else
% e.g. Enter an integer: 3,4
% e.g. Enter an integer: cha1r
   warning('Only integers are accepted.')

Answer 1

[Walter Roberson]

if mod(UserVar,1) == 0

OR

if UserVar == fix(UserVar)

There are other possibilities, too. Last year in CSSM we listed off at least a dozen different ways.

Answer 2

[Matt Fig]

A = [];

while 1
    userVar = input('Enter an integer, (or return to quit): ');
    if isempty(userVar)
        break
    elseif isnumeric(userVar) && fix(userVar)==userVar 
        A = [A userVar];
    else
        warning('Only integers are accepted.')
    end
end

A % Show what user entered (optional)

%

%

%

EDIT Changed FLOOR to FIX for negative integers, thanks to Walter.

[Walter Roberson]

floor vs fix wouldn't matter: you don't care which way a value gets rounded as long as the rounded value is not exactly equal to the original value except for integral values.

[Matt Fig]

True, D'oh!