MATLAB: Getting a function error “Output argument “z” (and maybe others) not assigned during call”

functions

Hey guys im new to matlab ive been trying to do a power function but I've been getting this error and Im not understanding why
Here is the function
function [z] = power1(x,y)
if y>=0
if y==0
z=1;
end
if y==1
z=x;
end
z=x*power1(x,y-1);
end
end

Best Answer

If y<0, variable z doesn't get any value assigned to it.
See the same question here here.