How to calculate Age based on a birthday in C#

Here is a sample code to calculate Age based on a birthday in C#.

using System;

public class HelloWorld
{
    public static void Main(string[] args)
    {
        DateTime birthdate = DateTime.ParseExact("1989-02-25", "yyyy-MM-dd",                                               System.Globalization.CultureInfo.InvariantCulture);
        var today = DateTime.Today;
        
        var age = today.Year - birthdate.Year;
        
        today.AddYears(-age);
        
        Console.WriteLine (age);
    }
}