PHP年龄计算器错误的年龄

Question

i've got an age calc script for PHP. But, it seems to work with some dates, i don't get why it wont work.

function Agecalc($birthday) 
{

    list($day,$month,$year) = explode("/",$birthday);
    $day_diff   = date("d") - $day;
    $month_diff = date("m") - $month;
    $year_diff  = date("Y") - $year;
    if ($day_diff < 0 || $month_diff < 0)
        $year_diff--;
    return $year_diff;

}

echo Agecalc('19/2/1994');

This returns "17" when it should be 18?

Answer 1

It is going to be beneficial to use PHP's built in DateTime functions to calculate this, specifically DateTime::diff(..).

function AgeCalc($birthday)
{
    $dateBirthday = DateTime::createFromFormat('d/m/Y', $birthday);
    $dateNow = new DateTime();
    $difference = $dateNow->diff($dateBirthday);
    return $difference->y;
}