public class Person
{
   public string FirstName { get; set; }
   public string LastName { get; set; }
   public string FullName
   {
       get
       {
                return FirstName + " " + LastName;
       }
   }
}

public string FullName
{
       get { return FirstName + " " + LastName; }
}

{ get { return your expression; } }

=> your expression;

public class Person
{
        public string FirstName { get; set; }
        public string LastName { get; set; }

        public string FullName => FirstName + " " + LastName;
}

public string this[int number]
{
            get
            {
                if (number >= 0 && number < _values.Length)
                {
                    return _values[number];
                }
                return "Error";
            }
}

public string this[int number] => (number >= 0 && number < _values.Length) ? _values[number] : "Error";

public override string ToString()
{
      return FirstName;
}

public override string ToString() => FirstName;

public int DoubleTheValue(int someValue) => someValue * 2;

public override string ToString()
{
       if (MiddleName != null)
       {
                return FirstName + " " + MiddleName + " " + LastName;
       }
       else
       {
                return FirstName + " " + LastName;
       }
}

public override string ToString() =>
                    (MiddleName != null)
                    ? FirstName + " " + MiddleName + " " + LastName
                    : FirstName + " " + LastName;

public IEnumerable<int> SmallNumbers()
{
    for (int i = 0; i < 10; i++)
        yield return i;
}

public IEnumerable<int> SmallNumbers() => from n in Enumerable.Range(0, 10)
                                                                         select n;

public IEnumerable<int> SmallNumbers() => Enumerable.Range(0, 10).Select(n => n);

برای پراپرتی‌ها:

<httpRuntime executionTimeout="1200" maxRequestLength="39936" />

using System;
using System.Configuration;
using System.Web.Configuration;

/// <summary>
/// کلاسی جهت نمایش اندازه مجاز فایل قابل ارسال به سرور
/// </summary>
public class CMaxLimit
{
  /// <summary>
  /// اندازه مجاز فایل قابل ارسال به سرور
  /// </summary>
  /// <returns></returns>
  public static string MaxFileUploadSizeLimit()
  {
      //مقدار پیش فرض
      int resultKB = 4096;

      //machine.config
      Configuration mConfig =
          WebConfigurationManager.OpenMachineConfiguration();
      bool mConfigIsLocked = false;
      HttpRuntimeSection section =
          mConfig.GetSection("system.web/httpRuntime") as HttpRuntimeSection;
      if (section != null)
      {
          resultKB = section.MaxRequestLength;
          mConfigIsLocked = section.ElementInformation.IsLocked;
      }

      //web.config
      if (!mConfigIsLocked)
      {
          HttpRuntimeSection httpRuntimeSection =
              WebConfigurationManager.GetSection("system.web/httpRuntime") as HttpRuntimeSection;
          if (httpRuntimeSection != null)
          {
              resultKB = httpRuntimeSection.MaxRequestLength;
          }
      }

      return
           SizeToString(resultKB * 1024);
  }

  /// <summary>
  /// نمایش اندازه یک فایل به صورتی قابل درک
  /// </summary>
  /// <param name="len">اندازه فایل</param>
  /// <returns></returns>
  public static string SizeToString(long len)
  {
      int order = 0;
      string[] sizes = new[] { "B", "KB", "MB", "GB" };
      while (len >= 1024 && order + 1 < sizes.Length)
      {
          order++;
          len = len / 1024;
      }
      return String.Format("{0:0.##} {1}", len, sizes[order]);
  }
}