MATLAB: Adding elements to a 2D array

arraysmatrix

Suppose matrix A=[ 1,2 ; 3,4 ; 5,6]

Matrix B=[ 7 , 8 ]

whever I use C=[A,B] I receive this error message

Error using ==> horzcat

CAT arguments dimensions are not consistent.

C = [A; B]

reshape(A',1,[])

 C(:, 2:2:2*size(B,2))=B;
 C(:, 1:2:end)=A;