func_num_args

Example 382. Demonstrate how func_num_args() works

<pre>
<?php
function demo ()
{
    $num_args = func_num_args();
    print "The function was passed $num_args argument(s).\n";
}

demo ();
demo ('A single argument');
demo ('multiple', 'arguments');
demo (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20);
?>
</pre>

Example 383. Show how func_num_args() and func_get_arg() can work together

<pre>
<?php
// Duplicate MySQL's interval() function
// Note the use of argument prototyping to ensure that
// if the function is called with less than the two required
// arguments, an error will be thrown.
function mysql_interval ($test_value, $interval_start)
{
    if ($test_value === NULL)
        return -1;

    $num_args = func_num_args ();

    // Loop through the argument list - starting after the first argument
    for ($index = 1; $index < $num_args; ++$index)
    {
        // Get the value of the current item in the list
        $current_value = func_get_arg ($index);

        // Try to find the first item that the test value is less than
        if ($test_value < $current_value && ! isset ($return_value))
            $return_value = $index - 1;

        // Make sure that the arguments match the proper format for the function
        if (! is_numeric ($current_value) || $current_value <= $last_value && isset ($last_value))
        {
            trigger_error ('The second and subsequent arguments to this function must be numbers '.
                "that increase in value from left to right.\n i.e. arg 1 < arg 2 < arg 3 ...",
                E_USER_WARNING);
            return FALSE;
        }

        $last_value = $current_value;
    }

    // If $test_value was less than one of the items in the argument list
    if (isset ($return_value))
        return $return_value;

    // If $test_value was not less than any of the other arguments
    return $index - 1;
}

print mysql_interval (1.5, 0, 1, 2, 3) . "\n";
print mysql_interval (9, 1, 2, 4, 8) . "\n";
print mysql_interval (9, -1, -2, -1, 4) . "\n";
?>
</pre>