A for loop that finds multiples of certain numbers in a given range

I am trying to create a for loop that finds all values in the range [1,100] that are also multiple of 3 or 5 and save these in a row vector labeled M1. It was suggested that I use mod()/rem() functions. I have been able to do this without a for loop, but when I try to use the for loop the answer is not in row vector form and there are a lot of blank answers.

x = [1:100];
i=1;
for k = 1:length(x)
    i=k(mod(k,3)==0)
    i=k(mod(k,5)==0)
end
M1=i

Answer 1

[David Hill]

y=[];
for k = 1:100
    if mod(k,3)==0||mod(k,5)==5
      y=[y,k];
    end
end
y

y = 1×33

3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69 72 75 78 81 84 87 90

[Garrett Viton]

This is not giving the multiples of 5 like 10, 20, 25, etc. What's the reasoning on this?

[Image Analyst]

@Garrett Viton, it's because there is an error in the code. See my answer below.

Answer 2

[Image Analyst]

Try this:

% Construct a list of values to check.  Call it x.
x = 1 : 100;
% Initialize our output row vector to null.  Then we'll fill it up.
M1=[];
% Now check all the values in x to see if they are a multiple of 3 or 5.
for k = 1 : length(x)
    % Get this value of x.
    this_x = x(k);
    % Check the value to see if it's a multiple of 3 or 5.
    if (mod(this_x, 3) == 0) || (mod(this_x, 5) == 0)
        % If we get here, this_x is a multiple of 3 or 5.
        % Store the value in our output vector.
        M1 = [M1, this_x];
    end
end
M1

M1 = 1×47

3 5 6 9 10 12 15 18 20 21 24 25 27 30 33 35 36 39 40 42 45 48 50 51 54 55 57 60 63 65