Age calculation from date of birth in PHP scripting language

<!-- Object based, reusable component approach in PHP 5 classes and objects -->
<?php
class DateOfBirth {

    private $current_num_year;
    private $current_num_month;
    private $current_num_day;

    private $current_num_month_days;

    public $birth_num_year;
    public $birth_num_month;
    public $birth_num_day;

    private $yy;
    private $mm;
    private $dd;

    public $age;

    public function DateOfBirth()
    {
        $this->current_num_year = date(Y);
        $this->current_num_month = date(n);
        $this->current_num_day = date(j);
        $this->current_num_month_days = date(t);
    }

    private function birthday_before_today()
    {
        $this->yy = $this->current_num_year - $this->birth_num_year;
        $this->mm = $this->current_num_month - $this->birth_num_month - 1;
        $this->dd = $this->birth_num_month_days - $this->birth_num_day + $this->current_num_day;
        if($this->dd > $this->current_num_month_days)
        {
            $this->mm += 1;
            $this->dd -= $this->current_num_month_days;
        }
    }

    private function birthday_on_today()
    {
        $this->yy = $this->current_num_year - $this->birth_num_year;
        $this->mm = 0;
        $this->dd = 0;
    }

    private function birthday_after_today()
    {
        $this->yy = $this->current_num_year - $this->birth_num_year - 1;
        $this->mm = $this->birth_num_month + $this->current_num_month - 1;
        $this->dd = $this->birth_num_month_days - $this->birth_num_day + $this->current_num_day;
        if($this->dd > $this->current_num_month_days)
        {
            $this->mm += 1;
            $this->dd -= $this->current_num_day;
        }
    }

    public function calculate_age()
    {
        $this->birth_num_month_days = date( t, mktime(0, 0, 0, $this->birth_num_month, $this->birth_num_day, $this->birth_num_year) );
        if($this->current_num_month > $this->birth_num_month)
        {
            $this->birthday_before_today();
        }
        if($this->current_num_month < $this->birth_num_month)
        {
            $this->birthday_after_today();
        }
        if($this->current_num_month == $this->birth_num_month)
        {
            if($this->current_num_day == $this->birth_num_day)
            {
                $this->birthday_on_today();
            }
            if($this->current_num_day < $this->birth_num_day)
            {
                $this->birthday_after_today();
            }
            if($this->current_num_day > $this->birth_num_day)
            {
                $this->birthday_before_today();
            }
        }
        $this->age = $this->yy . ' years, ' . $this->mm . ' months, ' . $this->dd . ' days';
    }

}

// $my_dob = new DateOfBirth(1981, 6, 23); // If Constructor (function) has arguments
$my_dob = new DateOfBirth();
$my_dob->birth_num_year = 1981;
$my_dob->birth_num_month = 6;
$my_dob->birth_num_day = 23;
$my_dob->calculate_age();
echo $my_dob->age;
?>

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<!-- mediasworks nonprofit public participation project -->

<!-- Object based, reusable component approach in PHP 4 classes and objects ( PHP 5 compatible ) -->
<?php
class DateOfBirth {

    var $current_num_year;
    var $current_num_month;
    var $current_num_day;

    var $current_num_month_days;

    var $birth_num_year;
    var $birth_num_month;
    var $birth_num_day;

    var $yy;
    var $mm;
    var $dd;

    var $age;

    function DateOfBirth()
    {
        $this->current_num_year = date(Y);
        $this->current_num_month = date(n);
        $this->current_num_day = date(j);
        $this->current_num_month_days = date(t);
    }

    function birthday_before_today()
    {
        $this->yy = $this->current_num_year - $this->birth_num_year;
        $this->mm = $this->current_num_month - $this->birth_num_month - 1;
        $this->dd = $this->birth_num_month_days - $this->birth_num_day + $this->current_num_day;
        if($this->dd > $this->current_num_month_days)
        {
            $this->mm += 1;
            $this->dd -= $this->current_num_month_days;
        }
    }

    function birthday_on_today()
    {
        $this->yy = $this->current_num_year - $this->birth_num_year;
        $this->mm = 0;
        $this->dd = 0;
    }

    function birthday_after_today()
    {
        $this->yy = $this->current_num_year - $this->birth_num_year - 1;
        $this->mm = $this->birth_num_month + $this->current_num_month - 1;
        $this->dd = $this->birth_num_month_days - $this->birth_num_day + $this->current_num_day;
        if($this->dd > $this->current_num_month_days)
        {
        $this->mm += 1;
        $this->dd -= $this->current_num_day;
        }
    }

    function calculate_age()
    {
        $this->birth_num_month_days = date( t, mktime(0, 0, 0, $this->birth_num_month, $this->birth_num_day, $this->birth_num_year) );
        if($this->current_num_month > $this->birth_num_month)
        {
            $this->birthday_before_today();
        }
        if($this->current_num_month < $this->birth_num_month)
        {
            $this->birthday_after_today();
        }
        if($this->current_num_month == $this->birth_num_month)
        {
            if($this->current_num_day == $this->birth_num_day)
            {
                $this->birthday_on_today();
            }
            if($this->current_num_day < $this->birth_num_day)
            {
                $this->birthday_after_today();
            }
            if($this->current_num_day > $this->birth_num_day)
            {
                $this->birthday_before_today();
            }
        }
        $this->age = $this->yy . ' years, ' . $this->mm . ' months, ' . $this->dd . ' days';
    }

}

// $my_dob = new DateOfBirth(1981, 6, 23); // If Constructor (function) has arguments
$my_dob = new DateOfBirth();
$my_dob->birth_num_year = 1981;
$my_dob->birth_num_month = 6;
$my_dob->birth_num_day = 23;
$my_dob->calculate_age();
echo $my_dob->age;
?>

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<!-- mediasworks Group, India and worldwide -->
<!-- mediasworks nonprofit public participation project -->

<!-- Functional, modular or structural approach in PHP -->
<?php
function calculate_age($birth_num_year, $birth_num_month, $birth_num_day)
{

    $birth_num_month_days = date( t, mktime(0, 0, 0, $birth_num_month, $birth_num_day, $birth_num_year) );

    $current_num_year = date(Y);
    $current_num_month = date(n);
    $current_num_day = date(j);
    $current_num_month_days = date(t);

    if($current_num_month > $birth_num_month)
    {
        $yy = $current_num_year - $birth_num_year;
        $mm = $current_num_month - $birth_num_month - 1;
        $dd = $birth_num_month_days - $birth_num_day + $current_num_day;
        if($dd > $current_num_month_days)
        {
            $mm += 1;
            $dd -= $current_num_month_days;
        }
    }

    if($current_num_month < $birth_num_month)
    {
        $yy = $current_num_year - $birth_num_year - 1;
        $mm = $birth_num_month + $current_num_month - 1;
        $dd = $birth_num_month_days - $birth_num_day + $current_num_day;
        if($dd > $current_num_month_days)
        {
            $mm += 1;
            $dd -= $current_num_day;
        }
    }

    if($current_num_month==$birth_num_month)
    {
        if($current_num_day == $birth_num_day)
        {
            $yy = $current_num_year - $birth_num_year;
            $mm = 0;
            $dd = 0;
        }
        if($current_num_day < $birth_num_day)
        {
            $yy = $current_num_year - $birth_num_year - 1;
            $mm = $birth_num_month + $current_num_month - 1;
            $dd = $birth_num_month_days - $birth_num_day + $current_num_day;
            if($dd > $current_num_month_days)
            {
                $mm += 1;
                $dd -= $current_num_day;
            }
        }
        if($current_num_day > $birth_num_day)
        {
            $yy = $current_num_year - $birth_num_year;
            $mm = $current_num_month - 1;
            $dd = $birth_num_month_days - $birth_num_day + $current_num_day;
            if($dd > $current_num_month_days)
            {
                $mm += 1;
                $mm -= $current_num_month;
                $dd -= $current_num_month_days;
            }
        }
    }

    $age = $yy . ' years, ' . $mm . ' months, ' . $dd . ' days';
    echo $age;
}

calculate_age(1981, 6, 23);
?>

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<!-- mediasworks Group, India and worldwide -->
<!-- mediasworks nonprofit public participation project -->