如何在LINQ .select中选择整数的最后一位？

Question

I have this LINQ select:

 var extendedPhrases = phrases
            .Select(x => new ExtendedPhrase()
            {
                Ajlpt = x.Ajlpt,
                Bjlpt = x.Bjlpt,
                Created = x.Created // an int?
            });

If I define:

public int? CreatedLast { get; set; }

Then how can I populate that with the last digit of x.Created?

Answer 1

If you are looking for the last digit of the Created property, the use the % operator like this:

var extendedPhrases = phrases
        .Select(x => new ExtendedPhrase()
        {
            Ajlpt = x.Ajlpt,
            Bjlpt = x.Bjlpt,
            Created = x.Created,
            CreatedLast = x.Created % 10
        });

Answer 2

The first way to come to mind is to call .ToString().Last():

var extendedPhrases = phrases
        .Select(x => new ExtendedPhrase()
        {
            Ajlpt = x.Ajlpt,
            Bjlpt = x.Bjlpt,
            Created = x.Created,
            CreatedLast = x.Created?.ToString().Last()
        });

If you aren't using the latest shiny C#, then null protection can be done with:

var extendedPhrases = phrases
        .Select(x => new ExtendedPhrase()
        {
            Ajlpt = x.Ajlpt,
            Bjlpt = x.Bjlpt,
            Created = x.Created,
            CreatedLast = x.Created.HasValue ? x.Created.ToString().Last() : null
        });

And some conversion back to an int? left as an exercise to the reader.