how to apply for loop for different vectors

I have two vectors or more depending upon the user, and I want to run the program many times depending upon this number of vectors. Then, for each run, I need to check the length of each vector and apply its related formulas depending upon the its length. I wrote the following program but it does not work, it takes only the second vector!!

M=[1 2 3 4];
M=[6 7 7 8 2 1 3 2];
k=length(M)
number_of_vectors=2;
for i=1:number_of_vectors
    if k==4
    h=M-1
    elseif k~=4
        h=M-3
    end
end

Answer 1

[Azzi Abdelmalek]

Use cell arrays

clear
V={[1 2 3 4],[6 7 7 8 2 1 3 2]}
number_of_vectors=numel(V);
for ii=1:number_of_vectors
  M=V{ii}
  k=numel(M)
  if k==4
      h{ii}=M-1
  else
      h{ii}=M-3
  end
end
celldisp(h)