Php/docs/function.func-num-args

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func_num_args

(PHP 4, PHP 5, PHP 7)

func_num_argsReturns the number of arguments passed to the function


说明

func_num_args ( ) : int

Gets the number of arguments passed to the function.

This function may be used in conjunction with func_get_arg() and func_get_args() to allow user-defined functions to accept variable-length argument lists.


返回值

Returns the number of arguments passed into the current user-defined function.


更新日志

版本 说明
5.3.0 This function can now be used in parameter lists.
5.3.0 If this function is called from the outermost scope of a file

which has been included by calling include or require from within a function in the calling file, it now generates a warning and returns -1.


错误/异常

Generates a warning if called from outside of a user-defined function.


范例

Example #1 func_num_args() example

<?phpfunction foo(){    $numargs = func_num_args();    echo "Number of arguments: $numargs\n";}foo(1, 2, 3);   ?>

以上例程会输出:


Number of arguments: 3

Example #2 func_num_args() example before and after PHP 5.3

test.php<?phpfunction foo() {    include './fna.php';}foo('First arg', 'Second arg');?>fna.php<?php$num_args = func_num_args();var_export($num_args);?>

Output previous to PHP 5.3:


2

Output in PHP 5.3 and later will be something similar to:


Warning: func_num_args():  Called from the global scope - no function
context in /home/torben/Desktop/code/ml/fna.php on line 3
-1

注释

Note:

因为函数依赖于当前作用域以确定参数的细节,所以在 5.3.0 以前的版本中不能用作函数的参数。如必须传递此值时,可将结果赋与一个变量,然后用此变量进行传递。

参见