What is the best validation route?

[miles_rich]

Ok i have coded some validation, is there a better way to do it, than put it in an if statement, so that multiple validations occour?

Here is the code:

<?php
include ("functions/customer_functions.php");

$firstname = ucwords(strtolower($firstname=$_REQUEST['firstname']));
$lastname = ucwords(strtolower($laname=$_REQUEST['lastname']));

if (ereg ("^[A-Z][a-z]+$", $firstname))
{
	if (ereg ("^[A-Z][a-z]+$", $lastname))
	{
		cust_add($firstname, $lastname); # Adds details to db.
	}
	else
	{
		echo "\"$lastname\" - is an invalid lastname!";
	}
}
else
{
echo "\"$firstname\" - is an invalid firstname!";
}
?>

is this a good way to do it?

[jesus_hairdo]

i would think that this IS the best way to do it.
The only quicker way to get a fault would be to combine the to if statements with a && (AND) statement.
The only problem then is you couldn't say which field was invalid.

[miles_rich]

say i had 8 fields would i still use nested ifs?

[jesus_hairdo]

i think that as the number got larger i wouldn't use nested ifs.

I use something like

$errorcount = 0;
if (!ereg ("^[A-Z][a-z]+$", $firstname)) //note the ! before the ereg, meaning if $firstname doesn't match then..
{
    $errorcount++;
    $errormsg .= "the firstname is not valid";
}
if (!ereg ("^[A-Z][a-z]+$", $surname)) //note the ! (not) before the ereg
{
    $errorcount ++;
    $errormsg .= "the field FIELDNAME2 is not valid";
}
...etc...
if ($errorcount > 0)
{
    print $errormsg;
    exit;
}
//if here is reached all the variables are valid.

[_SuperString]

heres a good way to do it:

$checks = array ("firstname", "lastname", "more");
foreach($checks as $cks) {
	$res = ereg ("^[A-Z][a-z]+$", $$cks);
	if(!$res) {
		if(!isset($error)) {
			$error = "These fields failed: ";
		}
		$error .= ", ".$$cks;
	}
}
if(isset($error)) {
	echo $error;
} else {
	echo "no errors!";
}

its really only ideal for lots of field checks with the same validation type. you could however add an other array that stores validation types.