Editing Exponentiation (section)

==In programming languages==
[[Programming language]]s generally express exponentiation either as an infix [[operator (computer programming)|operator]] or as a function application, as they do not support superscripts. The most common operator symbol for exponentiation is the [[caret]] (<code>^</code>). The [[ASCII#1963|original version of ASCII]] included an uparrow symbol (<code>↑</code>), intended for exponentiation, but this was [[caret#History|replaced by the caret]] in 1967, so the caret became usual in programming languages.<ref>{{cite book|author=Richard Gillam|title=Unicode Demystified: A Practical Programmer's Guide to the Encoding Standard|year=2003|isbn=0201700522|page=33|publisher=Addison-Wesley Professional }}</ref>
The notations include:
* <code>x ^ y</code>: [[AWK]], [[BASIC]], [[J programming language|J]], [[MATLAB]], [[Wolfram Language]] ([[Wolfram Mathematica|Mathematica]]), [[R (programming language)|R]], [[Microsoft Excel]], [[Analytica (software)|Analytica]], [[TeX]] (and its derivatives), [[TI-BASIC]], [[bc programming language|bc]] (for integer exponents), [[Haskell (programming language)|Haskell]] (for nonnegative integer exponents), [[Lua (programming language)|Lua]], and most [[computer algebra system]]s.
* <code>x ** y</code>. The [[Fortran]] character set did not include lowercase characters or punctuation symbols other than <code>+-*/()&amp;=.,'</code> and so used <code>**</code> for exponentiation<ref name="Sayre_1956"/><ref>{{citation|author1=Brice Carnahan|author2=James O. Wilkes|title=Introduction to Digital Computing and FORTRAN IV with MTS Applications|year=1968|pages=2-2, 2-6}}</ref> (the initial version used <code>a xx b</code> instead.<ref name="Backus_1954"/>). Many other languages followed suit: [[Ada (programming language)|Ada]], [[Z shell]], [[KornShell]], [[Bash (Unix shell)|Bash]], [[COBOL]], [[CoffeeScript]], [[Fortran]], [[FoxPro 2|FoxPro]], [[Gnuplot]], [[Apache Groovy|Groovy]], [[JavaScript]], [[OCaml]], [[Object REXX|ooRexx]], [[F Sharp (programming language)|F#]], [[Perl]], [[PHP]], [[PL/I]], [[Python (programming language)|Python]], [[Rexx]], [[Ruby (programming language)|Ruby]], [[SAS programming language|SAS]], [[Seed7]], [[Tcl]], [[ABAP]], [[Mercury (programming language)|Mercury]], Haskell (for floating-point exponents), [[Turing (programming language)|Turing]], and [[VHDL]].
* <code>x ↑ y</code>: [[Algol programming language|Algol Reference language]], [[Commodore BASIC]], [[TRS-80 Level II BASIC|TRS-80 Level II/III BASIC]].<ref name="InfoWorld_1982">{{cite news |title=BASCOM - A BASIC compiler for TRS-80 I and II |author-last=Daneliuk |author-first=Timothy "Tim" A. |date=1982-08-09 |newspaper=[[InfoWorld]] |series=Software Reviews |publisher=[[Popular Computing, Inc.]] |volume=4 |number=31 |pages=41–42 |url=https://books.google.com/books?id=NDAEAAAAMBAJ&pg=PA42 |access-date=2020-02-06 |url-status=live |archive-url=https://web.archive.org/web/20200207104336/https://books.google.de/books?id=NDAEAAAAMBAJ&pg=PA42&focus=viewport#v=onepage&q=TRS-80%20exponention |archive-date=2020-02-07}}</ref><ref name="80Micro_1983">{{cite journal |title=80 Contents |journal=[[80 Micro]] |publisher=[[1001001, Inc.]] |issn=0744-7868 |date=October 1983 |issue=45 |page=5 |url=https://archive.org/details/80-microcomputing-magazine-1983-10 |access-date=2020-02-06}}</ref>
* <code>x ^^ y</code>: Haskell (for fractional base, integer exponents), [[D (programming language)|D]].
* <code>x⋆y</code>: [[APL (programming language)|APL]].

In most programming languages with an infix exponentiation operator, it is [[operator associativity|right-associative]], that is, <code>a^b^c</code> is interpreted as <code>a^(b^c)</code>.<ref>{{cite book|author=Robert W. Sebesta|title=Concepts of Programming Languages|year=2010|isbn=978-0136073475|pages=130, 324|publisher=Addison-Wesley }}</ref> This is because <code>(a^b)^c</code> is equal to <code>a^(b*c)</code> and thus not as useful. In some languages, it is left-associative, notably in [[Algol]], [[MATLAB]], and the [[Microsoft Office Excel|Microsoft Excel]] formula language.

Other programming languages use functional notation:
* <code>(expt x y)</code>: [[Common Lisp]].
* <code>pown x y</code>: [[F Sharp (programming language)|F#]] (for integer base, integer exponent).

Still others only provide exponentiation as part of standard [[library (computing)|libraries]]:
* <code>pow(x, y)</code>: [[C (programming language)|C]], [[C++]] (in <code>math</code> library).
* <code>Math.Pow(x, y)</code>: [[C Sharp (programming language)|C#]].
* <code>math:pow(X, Y)</code>: [[Erlang (programming language)|Erlang]].
* <code>Math.pow(x, y)</code>: [[Java (programming language)|Java]].
* <code>[Math]::Pow(x, y)</code>: [[PowerShell]].
In some [[Type system|statically typed]] languages that prioritize [[type safety]] such as [[Rust (programming language)|Rust]], exponentiation is performed via a multitude of methods:

* <code>x.pow(y)</code> for <code>x</code> and <code>y</code> as integers
* <code>x.powf(y)</code> for <code>x</code> and <code>y</code> as floating-point numbers
* <code>x.powi(y)</code> for <code>x</code> as a float and <code>y</code> as an integer