Compare version numbers without using split function

How do I compare version numbers?

For instance:

x = 1.23.56.1487.5

y = 1.24.55.487.2

Can you use the Version class?
https://docs.microsoft.com/en-us/dotnet/api/system.version

It has an IComparable interface. Be aware this won't work with a 5-part version string like you've shown (is that really your version string?). Assuming your inputs are strings, here's a working sample with the normal .NET 4-part version string:

static class Program
{
    static void Main()
    {
        string v1 = "1.23.56.1487";
        string v2 = "1.24.55.487";

        var version1 = new Version(v1);
        var version2 = new Version(v2);

        var result = version1.CompareTo(version2);
        if (result > 0)
            Console.WriteLine("version1 is greater");
        else if (result < 0)
            Console.WriteLine("version2 is greater");
        else
            Console.WriteLine("versions are equal");
        return;

    }
}

If you can live with the major.minor.build.revision scheme you could use the .Net Version class. Otherwise you'd have to implement some kind of parsing from left to right and continuing until you have a difference or return that two versions are equal.

In addition to @JohnD 's answer there might be a need to compare only partial version numbers without using Split('.') or other string <-> int conversion bloat. I've just written an extension method CompareTo with 1 additional argument - number of significant parts of version number to compare (between 1 and 4).

public static class VersionExtensions
{
    public static int CompareTo(this Version version, Version otherVersion, int significantParts)
    {
        if(version == null)
        {
            throw new ArgumentNullException("version");
        }
        if(otherVersion == null)
        {
            return 1;
        }

        if(version.Major != otherVersion.Major && significantParts >= 1)
            if(version.Major > otherVersion.Major)
                return 1;
            else
                return -1;

        if(version.Minor != otherVersion.Minor && significantParts >= 2)
            if(version.Minor > otherVersion.Minor)
                return 1;
            else
                return -1;

        if(version.Build != otherVersion.Build && significantParts >= 3)
            if(version.Build > otherVersion.Build)
                return 1;
            else
                return -1;

        if(version.Revision != otherVersion.Revision && significantParts >= 4)
            if(version.Revision > otherVersion.Revision)
                return 1;
            else
                return -1;

        return 0; 
    }
}