Character input error message !!

Hello there, i want my inputs to be a positive number not a negative number or a text just positive number starting from zero, therefore i used this code,

m = str2num(get(handles.m,'string'));
v = str2num(get(handles.v,'string'));
if ( m >= 0 && v >= 0)
else
errordlg( 'The Inputs must be a positive numbers' )
end

This error is only for the negative values, i want to add if the input is text show an error so what should i add to this code .

Answer 1

[Giorgos Papakonstantinou]

If the string you get from handles.m is a char class then str2num will produce an empty matrix.

>> str2num('hello')
ans =
     []

Therefore, your else statement will be invoked and apparently, you will not have a problem. However, if you want to determine whether the item is character array you may use ischar.