  We provide unified implementations of the finite element methods involving
jumps and averages in Maltab by combing the use of the software package varFEM,
including the adaptive finite element methods for the Poisson equation and the
$C^0$ interior penalty methods for the biharmonic equation. The design ideas
can be extended to other Galerkin-based methods, for example, the discontinuous
Galerkin methods and the virtual element methods.
