Wolfram Language & System 11.0 (2016)|Legacy Documentation

This is documentation for an earlier version of the Wolfram Language.View current documentation (Version 11.2)

Testing Expressions

Wolfram Language symbolic expressions can represent an immense range of types of objects. The Wolfram Language provides a rich collection of functions to test expressions. Functions that "ask a question" have names that end in Q. They return True for an explicit true answer, and False otherwise.

ReferenceReference

Equality & Inequality

Equal (==), Unequal (!=) numerical equality

SameQ (===), UnsameQ (=!=) literal symbolic identity

Less (<)  ▪  Greater (>)  ▪  LessEqual (<=)  ▪  GreaterEqual (>=)  ▪  Between

Logical Combinations »

And(&&)  ▪  Or(||)  ▪  Not(!)  ▪  True  ▪  False  ▪  ...

AllTrue  ▪  AnyTrue  ▪  NoneTrue

Operator Forms

GreaterThan  ▪  LessThan  ▪  GreaterEqualThan  ▪  LessEqualThan  ▪  EqualTo  ▪  UnequalTo

Numerical Properties

NumberQ, MachineNumberQ literal number, literal machine-precision number

NumericQ numeric quantity (consisting of numbers, numeric constants, and functions)

IntegerQ  ▪  EvenQ  ▪  OddQ  ▪  PrimeQ  ▪  CoprimeQ  ▪  AlgebraicIntegerQ  ▪  ...

Positive  ▪  Negative  ▪  NonPositive  ▪  NonNegative  ▪  PossibleZeroQ

List-Oriented Tests

VectorQ, MatrixQ vector, matrix, perhaps with elements of specified types

ArrayQ full array of any depth

MemberQ test whether a pattern occurs in a list

DuplicateFreeQ  ▪  IntersectingQ  ▪  DisjointQ  ▪  SubsetQ

ContainsAll  ▪  ContainsNone  ▪  ContainsAny  ▪  ContainsOnly  ▪  ContainsExactly

Expression Tests

MatchQ test whether an expression matches a pattern

AtomQ  ▪  ListQ  ▪  TrueQ  ▪  BooleanQ  ▪  OrderedQ  ▪  PolynomialQ  ▪  DateObjectQ  ▪  TimeObjectQ

Order canonical ordering of expressions

String Tests »

StringQ  ▪  StringMatchQ  ▪  StringFreeQ  ▪  LetterQ  ▪  DigitQ  ▪  SyntaxQ  ▪  ...