A(I): index out of bounds; value 6 out of bound 5. How to fix this error?

%I'm trying to subtract the 2nd element from the 1st element

%The answer should be: 4-2=2, 6-4=2, 8-6=2, 10-8=2

a = [2:2:10];

b = [1:length(a)];

for index = a

a(b) = a(b+1) - a(b);

end

Answer 1

[KSSV]

a = [2:2:10];
b = zeros(1,length(a)-1);
for i = 1:length(a)-1
  b(i) = a(i+1) - a(i);
end

Or Simply:

b = diff(a)

b = 1×4

2 2 2 2