MATLAB: Systematically add entries to vector array

vector

Hi,
Given I have a vector as for instance: [ 1 3 5 7 1 3 …]
I want to add twice the number "8" after each entry, hence we would have:
[ 1 8 8 3 8 8 5 8 8 7 8 8 1 8 8 3 8 8 …]
How could I do that, in a way which would be not specific for the length of my initial array? Thanks

Best Answer

Here is one efficient method, without creating any temporary variables:
>> V = [1 3 5 7 1 3];
>> V(2:3,:) = 8;
>> V(:).'
ans =
1 8 8 3 8 8 5 8 8 7 8 8 1 8 8 3 8 8