func_get_arg
(PHP 4, PHP 5)
func_get_arg — Return an item from the argument list
說明
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.
參數
- arg_num
-
The argument offset. Function arguments are counted starting from zero.
Return值
Returns the specified argument, or FALSE on error.
錯誤/例外
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.
範例
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);
?>
註釋
Note: 因為這個函式依賴目前的範圍(scope)來決定參數，所以不能用當函式裡的參數使用。如果一定要傳入此數值，要將結果存入一個變數再傳入。
Note: This function returns a copy of the passed arguments only, and does not account for default (non-passed) arguments.