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


  • Any result for other than True is taken to signify failure.
  • The operator has a high precedence. Thus is , not .
  • In a form such as __?test every element in the sequence matched by must yield True when test is applied.

ExamplesExamplesopen allclose all

Basic Examples (1)Basic Examples (1)

Find cases of any expression which satisfies the NumberQ test:

Click for copyable input
New in 1
New to Mathematica? Find your learning path »
Have a question? Ask support »