The Wolfram Language's symbolic character allows a powerful unification of the notion of conditionals in programming and in mathematics.

Testing Expressions »

Equal(==)  ▪  Unequal(!=)  ▪  SameQ(===)  ▪  And(&&)  ▪  IntegerQ  ▪  ...

Procedural Conditionals

If test if a condition is true, false, or of unknown truth value

Which test which of a sequence of conditions are true

Switch switch based on a value, with patterns allowed

Mathematical Function Conditionals »

Piecewise an arbitrary piecewise function

ConditionalExpression expression defined under condition

UnitStep  ▪  Sign  ▪  Mod  ▪  Floor  ▪  Boole  ▪  DiscreteIndicator  ▪  ...

Pattern-Based Conditionals »

Replace replace an expression if a rule applies

Condition (/;) specify an arbitrary condition for a pattern to match

Functional Programming Conditionals »

NestWhile  ▪  TakeWhile  ▪  ...

List-Based Conditionals »

Select  ▪  Cases  ▪  Pick  ▪  ...

Program Execution Conditionals

Check  ▪  TimeConstrained  ▪  MemoryConstrained