UInt64.Equals Method (Object)

 

Returns a value indicating whether this instance is equal to a specified object.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

public override bool Equals(
	object obj
)

Parameters

obj
Type: System.Object

An object to compare to this instance.

Return Value

Type: System.Boolean

true if obj is an instance of UInt64 and equals the value of this instance; otherwise, false.

Notes to Callers:

Compiler overload resolution may account for an apparent difference in the behavior of the two Equals method overloads. If an implicit conversion between the obj argument and a UInt64 is defined and the argument is not typed as an Object, compilers perform an implicit conversion and call the Equals(UInt64) method. Otherwise, they call the Equals(Object) method, which always returns false if its obj argument is not a UInt64 value. The following example illustrates the difference in behavior between the two method overloads. In the case of the Byte, UInt16, and UInt32 values, the first comparison returns true because the compiler automatically performs a widening conversion and calls the Equals(UInt64) method, whereas the second comparison returns false because the compiler calls the Equals(Object) method.

using System;

public class Example
{
   static ulong value = 112;

   public static void Main()
   {
      byte byte1= 112;
      Console.WriteLine("value = byte1: {0,16}", value.Equals(byte1));
      TestObjectForEquality(byte1);

      short short1 = 112;
      Console.WriteLine("value = short1: {0,17}", value.Equals(short1));
      TestObjectForEquality(short1);

      int int1 = 112;
      Console.WriteLine("value = int1: {0,19}", value.Equals(int1));
      TestObjectForEquality(int1);

      sbyte sbyte1 = 112;
      Console.WriteLine("value = sbyte1: {0,17}", value.Equals(sbyte1));
      TestObjectForEquality(sbyte1);

      ushort ushort1 = 112;
      Console.WriteLine("value = ushort1: {0,16}", value.Equals(ushort1));
      TestObjectForEquality(ushort1);

      uint uint1 = 112;
      Console.WriteLine("value = uint1: {0,18}", value.Equals(uint1));
      TestObjectForEquality(uint1);

      decimal dec1 = 112m;
      Console.WriteLine("value = dec1: {0,21}", value.Equals(dec1));
      TestObjectForEquality(dec1);

      double dbl1 = 112;
      Console.WriteLine("value = dbl1: {0,20}", value.Equals(dbl1));
      TestObjectForEquality(dbl1);
   }

   private static void TestObjectForEquality(Object obj)
   {
      Console.WriteLine("{0} ({1}) = {2} ({3}): {4}\n",
                        value, value.GetType().Name,
                        obj, obj.GetType().Name,
                        value.Equals(obj));
   }
}
// The example displays the following output:
//       value = byte1:             True
//       112 (UInt64) = 112 (Byte): False
//
//       value = short1:             False
//       112 (UInt64) = 112 (Int16): False
//
//       value = int1:               False
//       112 (UInt64) = 112 (Int32): False
//
//       value = sbyte1:             False
//       112 (UInt64) = 112 (SByte): False
//
//       value = ushort1:             True
//       112 (UInt64) = 112 (UInt16): False
//
//       value = uint1:               True
//       112 (UInt64) = 112 (UInt32): False
//
//       value = dec1:                 False
//       112 (UInt64) = 112 (Decimal): False
//
//       value = dbl1:                False
//       112 (UInt64) = 112 (Double): False

The following example demonstrates the Equals method.

using System;

public class Example
{
   public static void Main()
   {
      object[] values = { (short) 10, (short) 20, 10, 20,
                          10L, 20L, 10D, 20D, (ushort) 10,
                          (ushort) 20, 10U, 20U,
                          10ul, 20ul };
      UInt64 baseValue = 20;
      String baseType = baseValue.GetType().Name;

      foreach (var value in values)
         Console.WriteLine("{0} ({1}) = {2} ({3}): {4}",
                           baseValue, baseType,
                           value, value.GetType().Name,
                           baseValue.Equals(value));

   }
}
// The example displays the following output:
//       20 (UInt64) = 10 (Int16): False
//       20 (UInt64) = 20 (Int16): False
//       20 (UInt64) = 10 (Int32): False
//       20 (UInt64) = 20 (Int32): False
//       20 (UInt64) = 10 (Int64): False
//       20 (UInt64) = 20 (Int64): False
//       20 (UInt64) = 10 (Double): False
//       20 (UInt64) = 20 (Double): False
//       20 (UInt64) = 10 (UInt16): False
//       20 (UInt64) = 20 (UInt16): False
//       20 (UInt64) = 10 (UInt32): False
//       20 (UInt64) = 20 (UInt32): False
//       20 (UInt64) = 10 (UInt64): False
//       20 (UInt64) = 20 (UInt64): True

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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