php birthday validation function - php

Question

I am trying to add a birthday validation function in my php script to make sure users are 18+. But I am stuck on how to add it in my if statement.
This is what is taken from the input fields:
$ydob = ($_POST['ydob']);
$mdob =($_POST['mdob']);
$ddob = ($_POST['ddob']);
$dob = $ddob."-".$mdob."-".$ydob;
The function:
function validateDOB($dob){
list($ydob,$mdob,$ddob) = explode("-",$dob);
$year_diff = date("Y") - $ydob;
$month_diff = date("m") - $mdob;
$day_diff = date("d") - $ddob;
if ($day_diff < 0 || $month_diff < 0) {
$year_diff--;
return $year_diff;
} }
This block is to check if all details are entered correctly. So my question is how would I add the function here to validate if the user is over 18.
if((!$username) || (!$country) || (!$dob) || (!$email) || (!$password)){
$error_message = "You did not submit the following required information!<br /><br />";
if(!$username){
$error_message .= "Enter a User Name";
} else if(!$country){
$error_message .= "Enter a Country";
} else if(!$dob){
$error_message .= "Enter a D.O.B";
} else if(!$email){
$error_message .= "Enter a Email Address";
} else if(!$password){
$error_message .= "Enter a Password";
}
} else {
....}
Thank you so much.
Ray

Answer 1

There's a much easier way to do it:
function validateDOB($date)
{
$minAge=strtotime("-18 YEAR");
$entrantAge= strtotime($date);
if ($entrantAge < $minAge)
{
return false;
}
return true;
}
And then:
if(validateDOB($date))
{
echo "Welcome";
}
else
{
echo "Sorry, you are too young";
}
EDIT: To convert your date from European date format to MySQL format, you can do this:
$ymd = DateTime::createFromFormat('d-m-Y', $dmy)->format('Y-m-d');
You can do that before you pass it through to the function, or you could do it inside the function. Up to you.

Answer 2

You have to add in your else statement:
else {
if(validateDOB($dob) <18)
{
$error_message .= "Not old enough<br />";
}
}

Answer 3

$date = '2010-11-05 18:55:21';
if (strtotime($date) !== false)
{
...
}

Answer 4

This Function returns True only if it is a valid date (also leap year) and also throw FALSE if it is not meeting your Application's minimum age requirement. Find Me On Best Social Network Fun n Enjoy ( http://www.myfne.com/ravinder )
function checkDOB($minage="-18 YEAR")
{
if(checkdate( $_POST["dob_month"] , $_POST["dob_day"] , $_POST["dob_year"])==TRUE){
return true;
}
$date=$_POST["dob_month"]."-".$_POST["dob_day"]."-".$_POST["dob_year"];
$minAge=strtotime($minage);
$entrantAge= strtotime($date);
if ($entrantAge > $minAge)
{
return true;
}
return false;
}