PHP: Hypertext Preprocessor (original) (raw)
func_num_args
(PHP 4, PHP 5, PHP 7, PHP 8)
func_num_args — Returns the number of arguments passed to the function
Description
func_num_args(): int
This function may be used in conjunction with func_get_arg() and func_get_args() to allow user-defined functions to accept variable-length argument lists.
Parameters
This function has no parameters.
Return Values
Returns the number of arguments passed into the current user-defined function.
Errors/Exceptions
Generates a warning if called from outside of a user-defined function.
Examples
Example #1 func_num_args() example
<?php function foo() { echo "Number of arguments: ", func_num_args(), PHP_EOL; }foo(1, 2, 3); ?>
The above example will output:
Notes
Note:
As of PHP 8.0.0, the func_*() family of functions is intended to be mostly transparent with regard to named arguments, by treating the arguments as if they were all passed positionally, and missing arguments are replaced with their defaults. This function ignores the collection of unknown named variadic arguments. Unknown named arguments which are collected can only be accessed through the variadic parameter.
See Also
- ... syntax
- func_get_arg() - Return an item from the argument list
- func_get_args() - Returns an array comprising a function's argument list
- ReflectionFunctionAbstract::getNumberOfParameters() - Gets number of parameters
Found A Problem?
19 years ago
`Just a note for anyone wondering. This function doesn't include params that have a default value, unless you pass one in to overwrite the default param value. Not sure if that makes sense, so here's an example:
`
Dennis Robinson from basnetworks dot net ¶
15 years ago
`This function comes in handy, and I believe is the only solution, when you have an optional parameter that can take any type of data.
For example:
The problem with the above function is that you will never be able to use null as the value for $data. To fix this, use func_num_args() like so:
= 2) { // Do something with $data // If you call my_function('something'), this WILL NOT be reached // If you call my_function('something', null), this WILL be reached } }?>This solution works because func_num_args() reports exactly how many arguments were passed when the function was called. It does not take into account when default argument values are used.
`
luisguillermo dot quevedovelez at gmail dot com ¶
13 years ago
`I had defined a function function_name(){ ...} as a drupal callback.
I try to get how many params where passed
I got a Error and my Site falls down
I've replaced func_get_args() instead func_num_args() and my Site was restored.
I conclude you can not use func_num_args() in callbacks.
Hope it helps.
`
thalis at NOSPAMcs dot pitt dot edu ¶
23 years ago
`The idea of func_get_args() is to construct functions of variable number of parameters like
`
ashley at dcs dot warwick dot ac dot uk ¶
23 years ago
`If you want to pass the parameters on intact to another function, use func_get_args and call_user_func_array (careful - this one is only available in recent PHP versions). For example:
i<i < i<numArgs; $i+=2) { echo " " . func_get_arg($i); if ($i+1 < $numArgs) echo "=\"" . func_get_arg($i+1) . "\""; } echo ">"; } /* Print an HTML tag with a newline on the end */ function printTagNL() { $args = func_get_args(); call_user_func_array("printTag", $args); echo "\n"; }printTagNL("input", "type", "hidden", "name", "SORTORDER", "value", $columnNo); ?>`
tongcheong77 at gmail dot com ¶
7 years ago
`If you are using PHP 7 and func_num_args is in your base class which you extended, you can pass your arguments with the 'spat' operator.
class Sql {
public function doGetWhere(...$args) {
$num_args = func_num_args();
$args_list = func_get_args();
echo '
';
var_dump($args_list);
echo '';
}
}class Member extends Sql {
public function getWhere(...$args) {
this−>doGetWhere(...this->doGetWhere(...this−>doGetWhere(...args);
}
}$member = new Member(); member−>getWhere(′firstname′,′lastname′,′userlevel′,′email′,′where′,′email′,′=′,member->getWhere('first_name','last_name','userlevel','email','where','email','=',member−>getWhere(′firstname′,′lastname′,′userlevel′,′email′,′where′,′email′,′=′,sub_email);
However, take note that if you 'new up' the 'Sql' class in your 'Member' class above, instead of extending it, you will not need to pass your arguments as a variable. Just my two cents. -Bruce tong
`