Problem in while loop when input is characters or words

 Hi all. I am trying to make a while loops that will keep on running if the user input is a str, a number less and equal 0 or the number is longer the length of my vector. But it doesn't work, plz help:)

    deleterowStr=input('Please enter the number of the row:','s');
    deleterow=str2num(deleterowStr);

    while ~((~isempty( choiceNum) &&  deleterow <=0 || deleterow > length(W)) || strcmpi(deleterowStr,'')==1)
    disp('Invaild row number')
    deleterowstr=input('Please enter the number of the row:','s');
    deleterow=str2num(deleterowstr);
    end

thx:)

Answer 1

[David Sanchez]

You do not say who is either W or choiceNum, but with the two variables in play, you can do it like this.

Watch the capital S in deleterowStr within the while loop

      deleterowStr = input('Please enter the number of the row:','s');
      deleterow = str2double(deleterowStr);

      while ~strcmpi(deleterowStr,'') || deleterow <= 0 
          disp('Invaild row number')
          deleterowStr = input('Please enter the number of the row:','s');
          deleterow = str2double(deleterowStr);
      end

[Jian Gui]

doesn't matlab displays:

Operands to the and && operators must be convertible to logical scalar values.

:(

[David Sanchez]

when you copy-paste the example i gave you, what's the error? What is your input?

[Jian Gui]

the matlab display the following message:

Operands to the and && operators must be convertible to logical scalar values.

and my W=[60 70 80]

[Jian Gui]

actually it works now, but i can't exit the while loops:S

[David Sanchez]

To exit the loop ( while-loop I gave you ) do not type anything and push Enter