How can i generalize "if statement"

Hi. everyone ~!

Thank you for reading^^

I'm a beginner to MATLAB, so please help me..!

I want to generalize "if statement" below for enlarging the size of instance.

In this code, I have described four variables(x(1), x(2), x(3), x(4)) in consideration of all possibilities.

I know that the way I code is very stupid...

how i can generalize in n variables...??

if (x(1)==1)&&(x(2)==1)&&(x(3)==1)&&(x(4)==1)
    edges = edges;
elseif (x(1)==1)&&(x(2)==1)&&(x(3)==1)
    edges = edges([1 2 3],:);
elseif (x(1)==1)&&(x(2)==1)&&(x(4)==1)
    edges = edges([1 2 4],:);
elseif (x(1)==1)&&(x(3)==1)&&(x(4)==1)
    edges = edges([1 3 4],:);
elseif (x(2)==1)&&(x(3)==1)&&(x(4)==1)
    edges = edges([2 3 4],:);
elseif (x(1)==1)&&(x(2)==1)
    edges = edges([1 2],:);
elseif (x(1)==1)&&(x(3)==1)
    edges = edges([1 3],:);
elseif (x(1)==1)&&(x(4)==1)
    edges = edges([1 4],:);
elseif (x(2)==1)&&(x(3)==1)
    edges = edges([2 3],:);
elseif (x(2)==1)&&(x(4)==1)
    edges = edges([2 4],:);
elseif (x(3)==1)&&(x(4)==1)
    edges = edges([3 4],:);
elseif (x(1)==1)
    edges = edges(1,:);
elseif (x(2)==1)
    edges = edges(2,:);
elseif (x(3)==1)
    edges = edges(3,:);
elseif (x(4)==1)
    edges = edges(4,:);
else 
    edges = [1 1 ; 2 2];
end

Answer 1

[Stephen23]

Assuming that x is a four-element numeric vector or logical vector, something like this should work:

if any(x)
    edges = edges(x==1,:);
else
    edges = [1,1;2,2];
end

You need to learn how to use logical indexing, which is a simple and powerful way to access data in arrays:

https://www.mathworks.com/company/newsletters/articles/matrix-indexing-in-matlab.html

https://www.mathworks.com/help/matlab/math/array-indexing.html

[연승 김]

Thank you!!! it works.

And I'll study about indexing in your links.

Thank you!!