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PHP5中文手册
Function handling
PHP Manual

func_get_arg

(PHP 4, PHP 5)

func_get_arg — Return an item from the argument list

说明

mixed func_get_arg ( int $arg_num )

Gets the specified argument from a user-defined function's argument list.

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

参数

arg_num

The argument offset. Function arguments are counted starting from zero.

返回值

Returns the specified argument, or FALSE on error.

错误／异常

Generates a warning if called from outside of a user-defined function, or if arg_num is greater than the number of arguments actually passed.

范例

Example#1 func_get_arg() example

<?php
function foo()
{
     $numargs = func_num_args();
     echo "Number of arguments: $numargs<br />\n";
     if ($numargs >= 2) {
         echo "Second argument is: " . func_get_arg(1) . "<br />\n";
     }
}

foo (1, 2, 3);
?>

注释

Note: Because this function depends on the current scope to determine parameter details, it cannot be used as a function parameter. If you must pass this value, assign the results to a variable, and pass the variable.

Note: This function returns a copy of the passed arguments only, and does not account for default (non-passed) arguments.

参见

Function handling
PHP Manual