C#:
Порівняння двох дат

How to (Як це зробити):

Here’s the straight-up way to compare dates in C#:

using System;

class DateComparison
{
    static void Main()
    {
        DateTime firstDate = new DateTime(2023, 4, 1);
        DateTime secondDate = DateTime.Now;
        
        // Comparison using DateTime.Compare
        int comparison = DateTime.Compare(firstDate, secondDate);
        
        // Outputs depending on the comparison
        if (comparison < 0)
        {
            Console.WriteLine("The first date is earlier than the second date.");
        }
        else if (comparison == 0)
        {
            Console.WriteLine("Both dates are identical.");
        }
        else
        {
            Console.WriteLine("The first date is later than the second date.");
        }
    }
}

Sample Output (depending on the current date, obviously):

The first date is earlier than the second date.

Deep Dive (Поглиблений аналіз):

Back in the day, date comparisons were cumbersome—think manual calculations or wrestling with less intuitive libraries. Now, the .NET Framework provides you with DateTime.Compare and overloads of comparison operators (<, >, ==, !=, <=, >=).

For alternatives, don’t overlook TimeSpan for duration between dates and DateTimeOffset to include time zones.

Implementation is straightforward; all the heavy lifting of accounting for leap years, different day counts in months, etc., is done by C#. Just ensure your system’s clock is correct or you’re in for a headache.

See Also (Додатково):

• MSDN Documentation on DateTime: docs.microsoft.com/en-us/dotnet/api/system.datetime
• More about TimeSpan: docs.microsoft.com/en-us/dotnet/api/system.timespan
• Comparing DateTimeOffset: docs.microsoft.com/en-us/dotnet/api/system.datetimeoffset