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# 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

例 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

> 注意: 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.

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

## 参见

func_get_args()
func_num_args()

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