Editing Named parameter (section)

== Emulating ==
In languages that do not support named parameters, some of the same benefits can be achieved in other ways.

=== With documentation ===
Their value as documentation can be replicated by tooltips in [[integrated development environment]]s (IDEs) for languages such as [[Java (programming language)|Java]], or with comments (in [[C (programming language)|C]]):
<syntaxhighlight lang="c">
MyFunctionCall(
    20,  /* x coordinate */
    50,  /* y coordinate */
    100, /* width */
    5,   /* height */
    TRUE /* drawing now? */
); 
</syntaxhighlight>

Such comments are not checked for correctness and the order of arguments remains important.

=== With data structures ===
Removing the argument order restriction, and the ability to leave some values unspecified, can be achieved by passing a [[record (computer science)|record]] or [[associative array]].

For example, in [[JavaScript]], these two calls are equivalent:
<syntaxhighlight lang="JavaScript">
MyFunctionCall({ xPosition: 20, yPosition: 50, width: 100, height: 5,
                 drawingNow: true });
</syntaxhighlight>
<syntaxhighlight lang="JavaScript">
MyFunctionCall({ width: 100, height: 5, xPosition: 20, yPosition: 50,
                 drawingNow: true });
</syntaxhighlight>

Compare to C99:<ref>{{Cite web|url=https://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html|title = Designated Inits (Using the GNU Compiler Collection (GCC))}}</ref>
<syntaxhighlight lang="c">
struct MyParam {
    int xPosition;
    int yPosition;
    int width;
    int height;
    unsigned char drawingNow;
};
…
MyParam parameters = { .xPosition = 20, .yPosition = 50,
        .width = 100, .height = 5, .drawingNow  = TRUE };
MyFunctionCall(&parameters);
</syntaxhighlight>

==== Special Support ====

In [[Perl]] and pre-2.0 [[Ruby (programming language)|Ruby]] a similar convention exists (generally called a ''hash'' or ''options hash''<ref>[https://docstore.mik.ua/orelly/perl/prog3/ch02_09.htm Programming Perl 2.9: Hashes]</ref>), with special support for omitting the delimiters within function calls. As an example, the core module's Net::FTP ''new'' function accepts a hash of optional arguments.<ref>[http://perldoc.perl.org/Net/FTP.html Perl core module Net::FTP]</ref>

=== With chained method calls ===
In [[object-oriented programming]] languages, it is possible to use [[method chaining]] to simulate named parameters, as a form of [[fluent interface]]. Each named-parameter argument is replaced with a method on an "arguments" object that modifies and then returns the object. In C++, this is termed the ''named parameter idiom''.<ref>C++ FAQ, [http://www.parashift.com/c++-faq-lite/ctors.html#faq-10.20 10.20 What is the "Named Parameter Idiom"?]</ref> The object may then be passed to a function that uses the arguments it contains.

[[Method chaining]] is often used in conjunction with the [[builder pattern]] as a way to override default values provided by the builder class.