If we have a plate with regularly spaced openings arranged in linear fashion we can observe more complex interference patterns.  In such an arrangement we get constructive interference in the forward direction from the plate.  As well as in the same directions that would give constructive interference from 2 nearest openings, if the light is in phase with that from its nearest neighbors, then light from all sources is in phase.  For example, at some angle the first crest emitted by a given opening is in phase with second crest emitted by the first neighbor, and with 3rd crest emitted by 2nd  neighbor and so on.  Thus, on a distant screen, bright fringes occur at the same spacing which are quiet bright, since all of the beams interfere constructively.
 Destructive interference is somewhat different.  A light source can cancel with its nearest neighbor as well as a neighbor 5 doors down.  Thus we can get many places where light interferes completely.  We have 200 regularly spaced openings, each acting as a light source.  The smallest angle of cancellation occurs when source 1 is out of phase with source 101, source 2 with source 102, etc.  So at 1/200 of the distance between the central fringe and the first bright fringe the intensity already dropped to zero.  Because there are so many possible bright fringes, they are very narrow.  Between bright fringes, there are many dark fringes, because there are many different ways for light to destructively interfere.  Between dark fringes there is little brightness, because the sources are never all in phase.
 

The spacing of fringes on a screen distance D away from plate can be found by multiplying wavelength of light by D and dividing that product by spacing between light sources.  Spacing = lD/d