Home > Article > Backend Development > How to dynamically obtain function parameter example code in php
How to dynamically obtain function parameter example code in php
- 伊谢尔伦Original
- 2017-06-26 13:51:291278browse
PHP supports variable number of argument lists in user custom functions. It's actually very simple, just use func_num_args() , func_get_arg() , and func_get_args() function.
Variable parametersNo special syntax is required. The parameter list is still passed to the function in the same way as the function definition, 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 ( 'a' , 'b' , 'c' );
?>Running result
参数个数为: 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 ( 'a' , 'b' , 'c' );
?>Running result
传入的参数分别为: array (size=3) 0 => string 'a' (length=1) 1 => string 'b' (length=1) 2 => string 'c' (length=1)
3.func_get_arg — Return parameter value from parameter list based on 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 ( 'a' , 'b' , 'c' );
?>Run result
参数个数为: 3 第二个参数为: b
The above is the detailed content of How to dynamically obtain function parameter example code in php. For more information, please follow other related articles on the PHP Chinese website!