Finding all numbers which is divisible by 5

Hello,

I would like to write a program which identifies all number which divisible by 5 by using while loop and mod.

Here is what I have so far.

a=input('Enter the threshold: ');
disp('Following number is devided by 5' + a);
number = 1;
while number<=a
    if mod(a,5)==0
         disp(a);
    end
    number=number+1
end
disp("The following numbers are divisible by 5: " + mod)

and the outcome display should look like this...

Enter the threshold: 100(For example)

The following numbers are divisible by 5: 5, 10, 15, 20 ...100(For example of threshold 100)

I really appreciate your response in advance!

[Geoff Hayes]

Takashi - one problem with the code is that on each iteration of the while loop, you are always using a with

    if mod(a,5)==0
         disp(a);
    end

Since a never changes, then I suspect that you want to be using number instead.

Do you need to use a while loop? Is this a condition of the assignment/homework?

Also, consider using fprint (instead of disp) to write out your messages and the numbers that are divisible by 5.

[Takashi Fukushima]

Yes I have to use while loop since it's homework.

I was wondering using number instead of a. Thanks for your info!

Answer 1

[Jeremy]

Hi,

In your mod command you want to compare the number variable to 5, not a (a doesn't change). This is why you're getting unexpected results. I would use zeroes to initialize z so that you can save each number that is divisible by 5 like:

a=input('Enter the threshold: ');
number = 1; z = zeros(1,a);
while number <= a
    if mod(number,5) == 0
         z(number) = number;
    end
    number=number+1;
end

And then use

find

to extract the indices of z that are nonzero and print them out.

I hope this helped

Answer 2

[Turlough Hughes]

This is your answer assuming the while loop is a must:

a=input('Enter the threshold: ');
disp("Following number is devided by 5: " + a);
number = 1;
count=1;
output=[];
while number<=a
    if mod(number,5)==0
         disp(number);
         output(count)=number;
         count=count+1;
    end
    number=number+1;
end
disp(['The following numbers are divisible by 5: ' num2str(output)])

Though you could do it also without a loop:

a=input('Enter the threshold: ');
disp("Following number is devided by 5: " + a);
range=1:a;
output=range(mod(range,5)==0)
disp(['The following numbers are divisible by 5: ' num2str(output)])