s : obj represents the pattern object obj, assigned the name s.

p?test is a pattern object that stands for any expression which matches p, and on which the application of test gives True.

PatternSequence[p_1, p_2, ...] is a pattern object which represents a sequence of arguments matching p_1, p_2, ....

In some cases you may need to specify pattern sequences that are more intricate than things like x__ or x..; for such situations you can use PatternSequence[p_1,p_2,…]. ...

HoldPattern[expr] is equivalent to expr for pattern matching, but maintains expr in an unevaluated form.

Pattern matching makes possible some of the most succinct and elegant programs in the Mathematica language—immediately compressing large numbers of conditional cases into ...

DatePattern[{"e_1", "e_2", ...}] represents the characters of a date with elements of type "e_i" in StringExpression. DatePattern[{"e_1", "e_2", ...}, sep] allows separators ...

Finding elements that match a pattern. This gives the elements of the list which match the pattern x^_. Here is the total number of elements which match the pattern.

OptionsPattern[] is a pattern object that represents a collection of options given as rules, where the values of the options can be accessed using OptionValue. ...

One of the unique strengths of Mathematica's core language is its powerful and succinct—yet highly readable—symbolic pattern language. Convenient both for immediate use in ...