Editing Nested function (section)

== Languages ==

Notable languages supporting nested functions include:

*[[ALGOL]]-based languages such as [[ALGOL 68]], [[Simula]], [[Pascal (programming language)|Pascal]], [[Modula-2]], [[Modula-3]], [[Oberon (programming language)|Oberon]], [[PL/I]], [[Seed7]] and [[Ada (programming language)|Ada]]
*Modern versions of [[Lisp (programming language)|Lisp]] (with lexical scope) such as [[Scheme (programming language)|Scheme]], and [[Common Lisp]]
*[[ECMAScript]] ([[JavaScript]] and [[ActionScript]])
*[[Dart (programming language)|Dart]]<ref>{{Cite web|url=https://dart.dev/guides/language/language-tour#lexical-scope|title=A tour of the Dart language}}</ref>
*[[Kotlin (programming language)|Kotlin]] (local functions<ref>{{Cite web|url=https://kotlinlang.org/docs/functions.html#local-functions|title = Functions &#124; Kotlin}}</ref>)
*[[Rust (programming language)|Rust]]
*[[Scala (programming language)|Scala]] (nested functions<ref>{{Cite web|url=https://docs.scala-lang.org/tour/nested-functions.html|title=Nested Methods}}</ref>)
*Various degrees of support in scripting languages such as [[Ruby (programming language)|Ruby]], [[Python (programming language)|Python]], [[Lua (programming language)|Lua]], [[PHP]] and [[Perl]]
*[[GNU Compiler Collection|GCC]] supports nested functions in C, as a language extension.<ref>{{cite web|url=https://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html|title=Nested Functions – Using the GNU Compiler Collection (GCC)|accessdate=2007-01-06|publisher=GNU Project}}</ref>
*[[C Sharp (programming language)|C#]], starting with C# 7.0
*The [[D (programming language)|D]] language, a C-related language with nested functions.
*[[Fortran]], starting with [[Fortran#Fortran 90|Fortran-90]], supports ''a single level'' of nested (''CONTAINed'') subroutines and functions.
*[[MATLAB]] (full support)
*[[Wolfram Language]]
*[[Go (programming language)| Golang]] (Function closures<ref>{{Cite web|url=https://go.dev/tour/moretypes/25|title=A tour of Go}}</ref>)

=== Functional languages ===

In most [[functional programming]] languages, such as Scheme, nested functions are a [[Programming idiom|common way]] of implementing [[algorithm]]s with loops in them. A simple ([[tail recursion|tail]]) [[recursion|recursive]] inner function is created, which behaves as the algorithm's main loop, while the outer function performs startup actions that only need to be done once. In more complex cases, a number of mutually recursive functions may be created as inner functions.