Detailed explanation of the steps to dynamically obtain function parameters in PHP

This time I will bring you a detailed explanation of the steps for dynamically obtaining function parameters in PHP, and what are the notes for dynamically obtaining function parameters in PHP. The following is a practical case, let's take a look.

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

Variable parametersNo special syntax is required. 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; );

Run 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 result

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 a parameter from the parameter list according to the parameter index Value

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

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

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