Riffle

Riffle[{e1,e2,},x]
gives {e1,x,e2,x,}.

Riffle[{e1,e2,},{x1,x2,}]
gives {e1,x1,e2,x2,}.

Riffle[list,x,n]
yields a list in which every n^(th) element is x.

Riffle[list,x,{imin,imax,n}]
yields a list in which x appears if possible at positions imin, imin+n, imin+2n, , imax.

DetailsDetails

  • If there are fewer xi than gaps between ei in Riffle[{e1,e2,},{x1,x2,}], the xi are used cyclically.
  • Riffle[{e},x] gives {e}.
  • The specification {imin,imax,n} is of the type used in Take. Negative indices count from the end of the list.
  • Riffle[list,x] is equivalent to Riffle[list,x,{2,-2,2}].
  • Riffle[list,x,n] is equivalent to Riffle[list,x,{n,-2,n}].
  • In Riffle[list,xlist], if list and xlist are of the same length, then their elements are directly interleaved, so that the last element of the result is the last element of xlist.
  • Riffle works with SparseArray objects.

ExamplesExamplesopen allclose all

Basic Examples  (3)Basic Examples  (3)

Riffle x between successive elements in a list:

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Riffle in x and y cyclically:

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Riffle in x at every 3^(rd) position:

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Introduced in 2007
(6.0)
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