I am trying to sort three numbers without using inbuilt functions.What is wrong with the function?

I am trying to sort three numbers without using inbuilt functions. The function takes a 3-element vector as its arguments and returns the 3 elements of the vector as 3 scalar output arguments in non-decreasing order.

function [small,medium,large] = sort_three(p)

    if p(1)<=p(2)
        if p(1)<=p(3)
            small=p(1);
        elseif p(1)>p(3)
            medium=p(1);
            small=p(3);
            large=p(2);
            return
        end
    elseif p(2)<=p(3)
        if p(2)<=p(1)
            small=p(2);
        elseif p(2)>p(1)
            small=p(1);
            medium=p(2);
            large=p(3);
            return
        end
    else
        small=p(3);
        medium=p(2);
        large=p(1);
        return
        end

[per isakson]

I think you get the error because you have misunderstood how if-elseif-else-end works. See if, elseif, else

Answer 1

[James Tursa]

Two of your branches do not set all three output variables. E.g.,

    if p(1)<=p(2)
        if p(1)<=p(3)
            small=p(1);  % <-- In this branch you never set medium and large
        elseif p(1)>p(3)
            :

And another branch later on has the same problem. So you need to fill in those branches. E.g.,

    if p(1)<=p(2)
        if p(1)<=p(3)
            small=p(1);  % <-- In this branch you never set medium and large
            if( p(2) <= p(3)
                medium = _____;
                large = _____;
            else
                medium = _____;
                large = _____;
            end
        else
            :

You need to fill in the blanks above, and do the same for the other branch that needs code.

Also, you need to account for all of the possible cases in your last branch. So you will need to add another if-then-else construct there.

[Souraj Adhikary]

Awesome answer