How to dynamically obtain function parameters in PHP

This article mainly introduces the method of dynamically obtaining function parameters in PHP. Now I will share it with you. Friends who need it can refer to it.

The example of this article describes the method of dynamically obtaining function parameters in PHP. Share it with everyone for your reference, the details are as follows:

PHP supports a variable number of parameter lists in user-defined functions. It's actually very simple, just use the func_num_args() , func_get_arg() , and func_get_args() functions.

Variable parameters do not require special syntax. The parameter list is still passed to the function in the way the function is defined, and these parameters are used in the usual way.

1. func_num_args — Returns the total number of parameters passed into the function

int func_num_args (void)

Example

<?php
function demo ()
{
  $numargs = func_num_args ();
  echo "参数个数为: $numargs \n" ;
}
demo ( &#39;a&#39; , &#39;b&#39; , &#39;c&#39; );

Running result

The number of parameters is: 3

2. func_get_args — Returns the parameter list passed into the function

array func_get_args (void)

Example

<?php
function demo ()
{
  $args = func_get_args();
  echo "传入的参数分别为:";
  var_dump($args);
}
demo ( &#39;a&#39; , &#39;b&#39; , &#39;c&#39; );

Running results

The parameters passed in are:
array (size=3)
0 => string 'a' (length=1)
1 => string 'b' (length=1)
2 => string 'c ' (length=1)

3. func_get_arg — Returns the parameter value from the parameter list according to the parameter index

mixed func_get_arg ( int $arg_num )

Example

<?php
function demo ()
{
  $numargs = func_num_args ();
  echo "参数个数为: $numargs <br />" ;
  $args = func_get_args();
  if ( $numargs >= 2 ) {
    echo "第二个参数为: " . func_get_arg ( 1 ) . "<br />" ;
  }
}
demo ( &#39;a&#39; , &#39;b&#39; , &#39;c&#39; );

Running result

The number of parameters is: 3
The second parameter is: b

The above is the detailed content of How to dynamically obtain function parameters in PHP. For more information, please follow other related articles on the PHP Chinese website!