Calculate age from BirthDate

Question

I have DatePicker Dialog, When I select date at that time I want to calculate age it\'s working but when I select date of current year at that time it showing the -1 age instead

Answer 1

public int getAge(int year, int month, int day) {
    final Calendar birthDay = Calendar.getInstance();
    birthDay.set(year, month, day);
    final Calendar current = Calendar.getInstance();
    if (current.getTimeInMillis() < birthDay.getTimeInMillis())
        throw new IllegalArgumentException("age < 0");
    int age = current.get(Calendar.YEAR) - birthDay.get(Calendar.YEAR);
    if (birthDay.get(Calendar.MONTH) > current.get(Calendar.MONTH) ||
            (birthDay.get(Calendar.MONTH) == current.get(Calendar.MONTH) &&
                    birthDay.get(Calendar.DATE) > current.get(Calendar.DATE)))
        age--;
    return age;
}