  We discuss the structure of the superconducting gap in iron pnictides. In the
itinerant electron picture, gaps with or without nodes have the extended s-wave
(s+) symmetry and emerge within the same pairing mechanism, determined by the
interplay between intra-pocket repulsion and inter-band pair hopping. If the
pair hopping is stronger, the system develops an s+ gap without nodes. In the
opposite case the superconductivity is governed by of the momentum-dependent
part of the pair-hopping, and an s+ gap shows nodes on electron Fermi surfaces.
We argue that the gap without/with nodes emerges in systems with a
stronger/weaker tendency towards a spin-density-wave order.
