(PHP 4, PHP 5, PHP 7, PHP 8)
func_num_args — Devuelve el número de argumentos pasados a la función
Obtiene el número de argumentos pasados a la función.
func_get_arg() puede ser utilizado conjuntamente con func_num_args() y func_get_args() para permitir que las funciones de usuario acepten un número variable de argumentos.
Esta función no tiene parámetros.
Devuelve el número de argumentos pasados a la función de usuario actual.
Genera una advertencia si es llamada fuera de una función de usuario.
Ejemplo #1 Ejemplo con func_num_args()
<?php
function foo()
{
echo "Número de argumentos: ", func_num_args(), PHP_EOL;
}
foo(1, 2, 3); // muestra ''
?>El resultado del ejemplo sería:
Número de argumentos: 3
Nota:
A partir de PHP 8.0.0, la familia de funciones func_*() está destinada a ser en su mayoría transparente con respecto a los argumentos con nombre, tratando los argumentos como si todos fueran pasados posicionalmente, y los argumentos faltantes son reemplazados por sus valores predeterminados. Esta función ignora la colección de argumentos variádicos con nombre desconocidos. Los argumentos con nombre desconocidos que se recopilan solo pueden accederse a través del parámetro variádico.
...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:
<?php
function helloWorld($ArgA, $ArgB="HelloWorld!") {
return func_num_args();
}
// The following will return 1
$Returns1 = helloWorld("HelloWorld!");
// The following will return 2
$Returns2 = helloWorld("HelloWorld!", "HowdyWorld!");
?>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:
<?php
// $data can be of any type, including null
function my_function($name, $data = null)
{
if ($data !== null)
{
// Do something with $data
// If you call my_function('something'), this WILL NOT be reached
// If you call my_function('something', null), this WILL NOT be reached
}
}
?>
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:
<?php
// $data can be of any type, including null
function my_function($name, $data = null)
{
if (func_num_args() >= 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.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.The idea of func_get_args() is to construct functions of variable number of parameters like
<?php
function var_param_func(){
if(func_num_args()==0){
//do one thing
}
if(func_num_args()==1)
//do another thing
//get the args with func_get_args()
}
}
?>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:
<?php
/* Print an HTML tag. This accepts a variable number of arguments:
the first should be the name of the tag, followed by pairs of
arguments that describe keys and values. The values are printed
with surrounding double quote characters. */
function printTag() {
$numArgs = func_num_args();
if ($numArgs < 1) die("printTag given no arguments");
echo "<" . func_get_arg(0);
for ($i = 1; $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", $columnNo);
?>If you are using PHP 7 and func_num_args is in your base class which you extended, you can pass your arguments with the 'spat' operator.
class Sql {
public function doGetWhere(...$args) {
$num_args = func_num_args();
$args_list = func_get_args();
echo '<pre>';
var_dump($args_list);
echo '<pre>';
}
}
class Member extends Sql {
public function getWhere(...$args) {
$this->doGetWhere(...$args);
}
}
$member = new Member();
$member->getWhere('first_name','last_name','userlevel','email','where','email','=',$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