func_get_arg
(PHP 4, PHP 5)
func_get_arg — Return an item from the argument list
说明
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.
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.
