Help with while loop programming

1)Add code that repeatedly prompts the user for a classification number, an integer from 1 to 4, until the user enters a valid classification number. Hint: use the floor() function to test for an integer value.

I made this program, but it only gives 0 or 1 and does not show disp

How can I fix this to show disp?

%this function will repeatedly prompt the user for a classification number

%until the user enters a valid classification number

classification = input('Enter your classification as an interger from 1 to 4: ');

TF = (5 > classification) && (classification > 0)

while (5 > classification) && (classification > 0) == 0

disp('INVALID INPUT - the number entered is not a valid classification number');

classification = input ('Please re-enter your classification as an interger from 1 to 4: ');

if (5 > classification) && (classification > 0) == 1

disp(classification)

disp('The interger entered is a valid classification number');

end

end

2)Add code that repeatedly displays a random integer from 1 to 6 (the roll of a die) until the first number displayed is redisplayed. Thus, numbers after the first number may be repeated any number of times, but the first number will be repeated exactly once. Hint: use the following expression to get a random integer from 1 to 6: floor(rand()*6) + 1

I am completely lost with this question

Answer 1

[Fangjun Jiang]

Almost there! Give it a meaningful but not confusion variable name, and don't repeat the same calculation.

%this function will repeatedly prompt the user for a classification number
%until the user enters a valid classification number
classification = input('Enter your classification as an interger from 1 to 4: ');
IsValid = (5 > classification) && (classification > 0);
while ~IsValid 
    disp('INVALID INPUT - the number entered is not a valid classification number');
    classification = input ('Please re-enter your classification as an interger from 1 to 4: ');
    IsValid = (5 > classification) && (classification > 0);
    if IsValid 
        disp(classification)
        disp('The interger entered is a valid classification number');
    end
end    

[Angel Washington]

Thank you!!! Would you happen to know how to do the second problem? I have an idea but don't know how to code if the number is repeated.

[Fangjun Jiang]

Very similar to this one. Roll the dice once, remember this "first number", then keep rolling the dice till the number rolled is the same as the "first number".

[Angel Washington]

%this function will repeatedly displays a random integer from 1 to 6 (the roll

%of a die) until the first number displayed is redisplayed

firstnumber = floor(rand()*6) + 1

while ~firstnumber

rollagain = floor(rand()*6) + 1

if firstnumber

disp('First number displayed is redisplayed');

end

end

I had something like this earlier, but I figured it was not on the right track