Clever way to append 's' for plural form in .Net (syntactic sugar)

Question

I want to be able to type something like:

Console.WriteLine(\"You have {0:life/lives} left.\", player.Lives);

instead of

Consol         


        

Answer 1

For C# 6.0 onwards, you can use Interpolated Strings to do this tricks.

Example:

    Console.WriteLine("\n --- For REGULAR NOUNS --- \n");
    {
        int count1 = 1;
        Console.WriteLine($"I have {count1} apple{(count1 == 1 ? "" : "s")}.");
        int count2 = 5;
        Console.WriteLine($"I have {count2} apple{(count2 == 1 ? "" : "s")}.");
    }

    Console.WriteLine("\n --- For IRREGULAR NOUNS --- \n");
    {
        int count1 = 1;
        Console.WriteLine($"He has {count1} {(count1 == 1 ? "leaf" : "leaves")}.");
        int count2 = 5;
        Console.WriteLine($"He has {count2} {(count2 == 1 ? "leaf" : "leaves")}.");
    }

Output:

 --- For REGULAR NOUNS --- 

I have 1 apple.
I have 5 apples.

 --- For IRREGULAR NOUNS --- 

He has 1 leaf.
He has 5 leaves.

You can play around on my .NET Fiddle.
For more details, go to Interpolated String documentation.

Answer 2

Looking at how strings are typically written that account for simultaneous single and multiple values, e.g.

"Expected {0} file(s), but found {1} file(s)."

The approach I took was to keep the same string, but add some parsing to determine whether the (s) should be removed completely, or to keep the s inside the round brackets. For irregular words, a slash can separate the singular and plural form.

Other examples:

• "Had {0:n2} child(ren)".Pluralize(1.0) => "Had 1.00 child"
• "Had {0} cherry(ies)".Pluralize(2) => "Had 2 cherries"
• "Had {0} calf/calves".Pluralize(1) => "Had 1 calf"
• "Had {0} son(s)-in-law".Pluralize(2) => "Had 2 sons-in-law"
• "Had {0} able seaman/seamen".Pluralize(1) => "Had 1 able seaman"
• "Had {0} sheep, {1} goat(s)".Pluralize(1, 2) => "Had 1 sheep, 2 goats"

///<summary>
/// Examples:
/// "{0} file(s)".Pluralize(1); -> "1 file"
/// "{0} file(s)".Pluralize(2); -> "2 files"
///</summary>
public static String Pluralize(this String s, params Object[] counts) {
    String[] arr = s.Split(new [] { ' ' }, StringSplitOptions.None);
    for (int i = 0; i < arr.Length; i++) {
        String t = arr[i];
        if (t.Length == 0 || t[0] != '{' || t[t.Length - 1] != '}')
            continue;

        int w = 1;
        while (w < t.Length) {
            char c = t[w];
            if (c < '0' || c > '9')
                break;
            w++;
        }

        if (w == 1)
            continue;

        int n = int.Parse(t.Substring(1, w-1));
        if (n >= counts.Length)
            continue;

        Object o = counts[n];
        if (o == null)
            continue;

        bool isSingle = false;
        if (o is int)
            isSingle = 1 == (int) o;
        else if (o is double)
            isSingle = 1 == (double) o;
        else if (o is float)
            isSingle = 1 == (float) o;
        else if (o is decimal)
            isSingle = 1 == (decimal) o;
        else if (o is byte)
            isSingle = 1 == (byte) o;
        else if (o is sbyte)
            isSingle = 1 == (sbyte) o;
        else if (o is short)
            isSingle = 1 == (short) o;
        else if (o is ushort)
            isSingle = 1 == (ushort) o;
        else if (o is uint)
            isSingle = 1 == (uint) o;
        else if (o is long)
            isSingle = 1 == (long) o;
        else if (o is ulong)
            isSingle = 1 == (ulong) o;
        else
            continue;

        for (int j = i + 1; j < arr.Length && j < i + 4; j++) {
            String u = arr[j];
            if (u.IndexOf('{') >= 0)
                break; // couldn't find plural word and ran into next token

            int b1 = u.IndexOf('(');
            int b2 = u.IndexOf(')', b1 + 1);
            if (b1 >= 0 && b2 >= 0) {
                String u1 = u.Substring(0, b1);
                String u2 = u.Substring(b2+1);
                char last = (u1.Length > 0 ? u1[u1.Length - 1] : ' ');
                String v = (isSingle ? "" : u.Substring(b1+1, (b2 - b1) - 1));
                if ((last == 'y' || last == 'Y') && String.Compare(v, "ies", true) == 0)
                    u1 = u1.TrimEnd('y', 'Y');

                arr[j] = u1 + v + u2;
                break;
            }
            int s1 = u.IndexOf('/');
            if (s1 >= 0) {
                arr[j] = (isSingle ? u.Substring(0, s1) : u.Substring(s1 + 1));
                break;
            }
        }
    }

    s = String.Join(" ", arr);
    s = String.Format(s, counts);
    return s;
}

Answer 3

string message = string.format("You have {0} left.", player.Lives == 1 ? "life" : "lives");

Of course this assumes that you have a finite number of values to pluralize.

Answer 4

You may checkout the PluralizationService class which is part of the .NET 4.0 framework:

string lives = "life";
if (player.Lives != 1)
{
    lives = PluralizationService
        .CreateService(new CultureInfo("en-US"))
        .Pluralize(lives);
}
Console.WriteLine("You have {0} {1} left", player.Lives, lives);

It is worth noting that only English is supported for the moment. Warning, this don't work on the Net Framework 4.0 Client Profile!

You could also write an extension method:

public static string Pluralize(this string value, int count)
{
    if (count == 1)
    {
        return value;
    }
    return PluralizationService
        .CreateService(new CultureInfo("en-US"))
        .Pluralize(value);
}

And then:

Console.WriteLine(
    "You have {0} {1} left", player.Lives, "life".Pluralize(player.Lives)
);

Answer 5

I did a little bit of work with PluralizationService and came up with. I just made the PluralizationService static for performance and combined all.

Reference System.Data.Entity.Design

  using System.Data.Entity.Design.PluralizationServices;
  using System.Reflection;

  public static class Strings
  {
    private static PluralizationService pluralizationService = PluralizationService.CreateService(System.Globalization.CultureInfo.CurrentUICulture);
    public static string Pluralize(this MemberInfo memberInfo)//types, propertyinfos, ect
    {
      return Pluralize(memberInfo.Name.StripEnd());
    }

    public static string Pluralize(this string name)
    {
      return pluralizationService.Pluralize(name); // remove EF type suffix, if any
    }

    public static string StripEnd(this string name)
    {
      return name.Split('_')[0];
    }
  }

Answer 6

I am using this extension method with .NET 4.6

public static string Pluralize(this string @string)
{
     if (string.IsNullOrEmpty(@string)) return string.Empty;

     var service = new EnglishPluralizationService();

     return service.Pluralize(@string);
}