Function

A function produces a return value from a list of argument values.

Related concepts:  OperatorParameterArgumentReturnMethod

Closest Wikipedia entry:  Subroutine — In computer programming, a function (also procedure, method, subroutine, routine, or subprogram) is a callable unit of software logic that has a well-defined interface and behavior and can be invoked multiple times. Callable units provide a powerful programming tool. The primary purpose is to allow for the decomposition of a large and/or complicated problem into chunks that have relatively low cognitive load and to assign the chunks meaningful names (unless they are anonymous).

Misconceptions about Function

15 documented Misconceptions

ArrowFunctionNoImpliedReturn — JavaScript

Even when an arrow function consists just of an expression, the return keyword must be explicitly written

ArrowFunctionRequiresFunctionKeyword — JavaScript

Arrow functions also require the keyword 'function'

CallbackParametersInCaller — JavaScript

Parameters of a callback function may be written as parameters of the caller function

DeferredReturn — Python

A return statement in the middle of a function doesn't return immediately

FunctionAsValueWithParentheses — JavaScript

To use a function as a value, one needs to have parentheses after its name

FunctionOverloading — JavaScript

It is possible to create multiple functions with the same name but with different signatures

FunctionsCannotBeImmediatelyInvoked — JavaScript

Functions cannot be called in the expression in which they are defined

FunctionsMustBeNamed — JavaScript

Every function definition requires an associated name

MultipleValuesReturn — Python

Functions can return multiple values

NoFunctionCallsChaining — JavaScript

It is not allowed to chain function calls

NumberOfParametersMatchArguments — JavaScript

Functions must be called with the same number of arguments as defined in their signature

OutsideInFunctionNesting — Python

Nested function calls are invoked outside in

OutsideInMethodNesting — Java

Nested method calls are invoked outside in

ParenthesesOnlyIfArgument — Python

() are optional for function calls without arguments

ReturnCall — Python

Return statements need () around the return value