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Line 232:
(lambda (arg) (* arg arg))
</source>
===Python===▼
[[Python (programming language)|Python]] supports anonymous functions through the lambda form. It is, however, expected to be only a single line of code and always returns whatever that line returns. For example:▼
<source lang="python">▼
foo = lambda x: x*x▼
print foo(10)▼
</source>▼
The lambda function ''always'' returns x*x and there is no way for a lambda function to not return something. This makes anonymous functions limited and are not simply nameless functions.▼
===PHP===▼
[[PHP]] doesn't have true anonymous functions because the only way to reference functions is by name. The closest PHP is shown in the following.▼
<source lang="php">▼
$foo = create_function('$x', 'return $x*$x;');▼
$bar = create_function("\$x", "return \$x*\$x;");▼
echo $foo(10);▼
</source>▼
As of 5.2.5, the contents of $foo is a string of the form "\0lambda_X" where \0 is a null character (ASCII value zero) and X is a number starting with one.▼
It is important to note that the argument list and function body must be in single quotes or the dollar signs must be escaped.▼
Otherwise PHP will assume "$x" means the variable $x and will substitute it into the string (despite possibly not existing) instead of leaving "$x" in the string.▼
For functions with quotes or functions with lots of variables, it can get quite tedious to ensure the intended function body is what PHP interprets.▼
===Perl===
Line 282 ⟶ 259:
my @bad_example = map { print for @_ } 1..10; # values not passed like normal Perl function
</source>
▲===PHP===
▲[[PHP]] doesn't have true anonymous functions because the only way to reference functions is by name. The closest PHP is shown in the following.
▲<source lang="php">
▲$foo = create_function('$x', 'return $x*$x;');
▲$bar = create_function("\$x", "return \$x*\$x;");
▲echo $foo(10);
▲</source>
▲As of 5.2.5, the contents of $foo is a string of the form "\0lambda_X" where \0 is a null character (ASCII value zero) and X is a number starting with one.
▲It is important to note that the argument list and function body must be in single quotes or the dollar signs must be escaped.
▲Otherwise PHP will assume "$x" means the variable $x and will substitute it into the string (despite possibly not existing) instead of leaving "$x" in the string.
▲For functions with quotes or functions with lots of variables, it can get quite tedious to ensure the intended function body is what PHP interprets.
▲===Python===
▲[[Python (programming language)|Python]] supports anonymous functions through the lambda form. It is, however, expected to be only a single line of code and always returns whatever that line returns. For example:
▲<source lang="python">
▲foo = lambda x: x*x
▲print foo(10)
▲</source>
▲The lambda function ''always'' returns x*x and there is no way for a lambda function to not return something. This makes anonymous functions limited and are not simply nameless functions.
[[de:Anonyme Subroutine]]
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