Variadic function: Difference between revisions

=={{header|ActionScript}}==

public function printArgs(... args):void

{

trace(args[i]);

}

=={{header|ALGOL 68}}==

The parameter list does not pass information about parameter type. If necessary, the type information has to be passed for example in the first parameter.

C calling convention has to be used (with keyword cdecl).

SUB printAll cdecl (count As Integer, ... )

DIM arg AS Any Ptr

printAll 3, 3.1415, 1.4142, 2.71828

For some reason, I was not able to get a Strings version of the above to work.

=={{header|C}}==

The ANSI C standard header stdarg.h defines macros for low-level access to the parameter stack. It does not know the number or types of these parameters; this is specified by the required initial parameter(s). For example, it could be a simple count or a more complicated parameter specification, like a printf() format string.

#include <stdarg.h>

}

=={{header|Common Lisp}}==

(defun example (&rest args)

{{works with|Java|1.5+}}

Using <tt>...</tt> after the type of argument will take in any number of arguments and put them all in one array of the given type with the given name.

for(Object i:things){

System.out.println(i);

}

This function can be called with any number of arguments:

printAll(4, 3, 5);

Or with an array directly:

=={{header|JavaScript}}==

for (var i=0; i<arguments.length; i++)

print(arguments[i])

printAll(4, 3, 5, 6, 4, 3);

printAll(4, 3, 5);

=={{header|Logo}}==

=={{header|Perl}}==

foreach (@_) {

print "$_\n";

}

This function can be called with any number of arguments:

print_all(4, 3, 5);

Since lists are flattened when placed in a list context, you can just pass an array in as an argument and all its elements will become separate arguments:

=={{header|PHP}}==

foreach (func_get_args() as $x) // first way

echo "$x\n";

printAll(4, 3, 5, 6, 4, 3);

printAll(4, 3, 5);

=={{header|Python}}==

Putting <tt>*</tt> before an argument will take in any number of arguments and put them all in a tuple with the given name.

for x in things:

This function can be called with any number of arguments:

print_all(4, 3, 5)

You can use the same "*" syntax to apply the function to an existing list of arguments:

===Keyword arguments ===

Python also has keyword arguments were you can add arbitrary ''func('''''keyword1=value1, keyword2=value2 ...''''')'' keyword-value pairs when calling a function.

This example shows both keyword arguments and positional arguments. The two calls to the function are equivalent. '''*alist''' spreads the members of the list to create positional arguments, and '''**adict''' does similar for the keyword/value pairs from the dictionary.

print "POSITIONAL ARGS:\n " + "\n ".join(repr(x) for x in positionalargs)

print "KEYWORD ARGS:\n " + '\n '.join(

'fee' = 'fi'

'fo' = 'fum'

=={{header|RapidQ}}==

=={{header|Ruby}}==

The * is sometimes referred to as the "splat" in Ruby.

things.each { |x| puts x }

This function can be called with any number of arguments:

print_all(4, 3, 5)

You can use the same "*" syntax to apply the function to an existing list of arguments:

=={{header|Scheme}}==

Putting a dot before the last argument will take in any number of arguments and put them all in a list with the given name.

(for-each

(lambda (x) (display x) (newline))

(lambda things

(for-each

(lambda (x) (display x) (newline))

This function can be called with any number of arguments:

(print-all 4 3 5)

=={{header|V}}==