BUILT-IN MATHEMATICA SYMBOL

MapIndexed

MapIndexed[f, expr]
applies f to the elements of expr, giving the part specification of each element as a second argument to f.

MapIndexed[f, expr, levelspec]
applies f to all parts of expr on levels specified by levelspec.

Details and Options Details and Options

MapIndexed uses standard level specifications:
n levels through n

Infinity levels through Infinity

{n} level n only

{n₁,n₂} levels through
The default value for levelspec in MapIndexed is .
A positive level n consists of all parts of expr specified by n indices.
A negative level -n consists of all parts of expr with depth n.
Level consists of numbers, symbols, and other objects that do not have subparts.
Level corresponds to the whole expression.
With the option setting Heads->True, MapIndexed also applies to heads of expressions and their parts.
MapIndexed traverses the parts of expr in a depth-first order, with leaves visited before roots. »
MapIndexed always effectively constructs a complete new expression and then evaluates it.