func_num

Description

int func_num_args ( void )

Returns the number of arguments passed into the current user-defined function. func_num_args() will generate a warning if called from outside of a user-defined function. This function cannot be used directly as a function parameter. Instead, its result may be assigned to a variable, which can then be passed to the function.

注: 因為本函數依賴於現用的功能變數來決定參數細節，因此不能用作函數參數。若果必須要傳遞這個值，將結果賦給一個變量，然後傳遞該變量。


<?php
function foo() 
{
    $numargs = func_num_args();
    echo "Number of arguments: $numargs\n";
} 

foo(1, 2, 3);    // Prints 'Number of arguments: 3'
?>

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