Editing Arity (section)

=== Ternary ===
The computer programming language [[C (programming language)|C]] and its various descendants (including [[C++]], [[C Sharp (programming language)|C#]], [[Java (programming language)|Java]], [[Julia (programming language)|Julia]], [[Perl]], and others) provide the [[ternary conditional operator]] <code>?:</code>. The first operand (the condition) is evaluated, and if it is true, the result of the entire expression is the value of the second operand, otherwise it is the value of the third operand. This operator has a lazy or 'shortcut' [[evaluation strategy]] that does not evaluate whichever of the second and third arguments is not used. Some functional programming languages, such as [[Agda (programming language)|Agda]], have such an evaluation strategy for all functions and consequently implement {{code|if...then...else}} as an ordinary function; several others, such as [[Haskell]], can do this but for syntactic, performance or historical reasons choose to define keywords instead.

The [[Python (programming language)|Python]] language has a ternary conditional expression, {{code|x if C else y|python}}. In [[Elixir (programming language)|Elixir]] the equivalent would be {{code|if(C, do: x, else: y)|elixir}}.

The [[Forth (programming language)|Forth]] language also contains a ternary operator, <code>*/</code>, which multiplies the first two (one-cell) numbers, dividing by the third, with the intermediate result being a double cell number. This is used when the intermediate result would overflow a single cell.

The Unix [[dc (computer program)|dc calculator]] has several ternary operators, such as <code>|</code>, which will pop three values from the stack and efficiently compute <math display="inline">x^y \bmod z</math> with [[arbitrary-precision arithmetic|arbitrary precision]].

Many ([[Reduced instruction set computing|RISC]]) [[assembly language]] instructions are ternary (as opposed to only two operands specified in CISC); or higher, such as <syntaxhighlight lang="asm" inline="">MOV %AX, (%BX, %CX)</syntaxhighlight>, which will load ({{mono|MOV}}) into register {{mono|AX}} the contents of a calculated memory location that is the sum (parenthesis) of the registers {{mono|BX}} and {{mono|CX}}.<!-- examples section needs complete rewrite, with links and subsection on math, logic and programming
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