While Loop Question - Will not Properly Execute

% Until good gender, prompt user to enter the gender

y = input ( 'Is the person female(1) or male(2)? Enter 1 or 2: ' );
while (y ~= 1) || (y ~= 2)
    disp( 'not 1 or 2' )
    y = input ( 'Is the person female(1) or male(2)? Enter 1 or 2: ' );
end

Can anyone tell me why this will not properly execute when ran through MATLAB?

Answer 1

[Geoff Hayes]

Josh - consider your conditions for the while loop

while (y ~= 1) || (y ~= 2)

which is saying that if the input is not 1 (female) or not 2 (male) then ask the user to enter in a gender again. What you really want to say is if the input is not 1 AND not 2 then... (i.e. not female and not male) and so your code becomes

while (y ~= 1) && (y ~= 2)