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Documentation / Mathematica / Built-in Functions / Programming / Functional Programming /

Scan

FilledSmallSquare Scan[f, expr] evaluates f applied to each element of expr in turn.

FilledSmallSquare Scan[f, expr, levelspec] applies f to parts of expr specified by levelspec.

FilledSmallSquare Scan[f, expr] discards the results of applying f to the subexpressions in expr. Unlike Map, Scan does not build up a new expression to return.

FilledSmallSquare You can use Return to exit from Scan. Return[ret] causes the final value of Scan to be ret. If no explicit return values are specified, the final result from Scan is Null.

FilledSmallSquare You can also use Throw to exit from Scan.

FilledSmallSquare Scan is useful in carrying out an operation on parts of expressions where the operation has a "side effect", such as making an assignment.

FilledSmallSquare Level specifications are described in Section A.3.6.

FilledSmallSquare The default value for levelspec in Scan is {1}.

FilledSmallSquare If expr is a SparseArray object, Scan[f, expr] applies f only to the values or subarrays that explicitly appear in expr.

FilledSmallSquare See Section 2.2.4.

FilledSmallSquare See also: Apply, Map, Level, Sow.

FilledSmallSquare New in Version 1; modified in 3.

Further Examples