(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.
Esta función se puede usar junto con func_get_arg() y func_get_args() para permitir a las funciones definidas por el usuario aceptar listas de argumentos de longitud variable.
Esta función no tiene parámetros.
Devuelve el número de argumentos pasados a la función actual definida por el usuario.
Genera una advertencia si se llama desde fuera de una función definida por el usuario.
Ejemplo #1 Ejemplo de func_num_args()
<?php
function foo()
{
$númargs = func_num_args();
echo "Número de argumentos: $númargs\n";
}
foo(1, 2, 3);
?>
El resultado del ejemplo sería:
Número de argumentos: 3
Just a note for anyone wondering. This function doesn't include params that have a default value, unless you pass one in to overwrite the default param value. Not sure if that makes sense, so here's an example:
<?php
function helloWorld($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 $data
// If you call my_function('something'), this WILL NOT be reached
// If you call my_function('something', null), this WILL be reached
}
}
?>
This solution works because func_num_args() reports exactly how many arguments were passed when the function was called. It does not take into account when default argument values are used.
I had defined a function function_name(){ ...} as a drupal callback.
I try to get how many params where passed
I got a Error and my Site falls down
I've replaced func_get_args() instead func_num_args() and my Site was restored.
I conclude you can not use func_num_args() in callbacks.
Hope it helps.
The idea of func_get_args() is to construct functions of variable number of parameters like
<?php
function var_param_func(){
if(func_num_args()==0){
//do one thing
}
if(func_num_args()==1)
//do another thing
//get the args with func_get_args()
}
}
?>
If you are using PHP 7 and func_num_args is in your base class which you extended, you can pass your arguments with the 'spat' operator.
class Sql {
public function doGetWhere(...$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
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);
?>
func_num_args() can be used in conjunction with named arguments, also. For example:
<?php
function DebugShow( $label, $value ) {
echo "# " . $label ;
if ( func_num_args() > 1 ) echo " = " . $value ;
echo "<br>";
}
?>
