Documentation

Mathematica Teacher's Edition

Built-in Functions

Programming

Pattern Matching

DeleteCases

DeleteCases[expr, pattern] removes all elements of expr which match pattern.
DeleteCases[expr, pattern, levspec] removes all parts of expr on levels specified by levspec which match pattern.
DeleteCases[expr, pattern, levspec, n] removes the first n parts of expr which match pattern.

Example: DeleteCases[1, a, 2, b, _Integer].
Level specifications are described in Section A.3.6.
See The Mathematica Book on the web: Section 2.3.2.
See also: Cases, ReplaceAll, Delete.

Further Examples