Supports all classes in the .NET Framework class hierarchy and provides low-level services to derived classes. This is the ultimate base class of all classes in the .NET Framework; it is the root of the type hierarchy.

Inheritance Hierarchy
System..::.Object All classes, structures, enumerations, and delegates.
Namespace:
System Assembly:
mscorlib (in mscorlib.dll)

Syntax
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
<ClassInterfaceAttribute(ClassInterfaceType.AutoDual)> _
Public Class Object
[SerializableAttribute]
[ComVisibleAttribute(true)]
[ClassInterfaceAttribute(ClassInterfaceType.AutoDual)]
public class Object
[SerializableAttribute]
[ComVisibleAttribute(true)]
[ClassInterfaceAttribute(ClassInterfaceType::AutoDual)]
public ref class Object
[<SerializableAttribute>]
[<ComVisibleAttribute(true)>]
[<ClassInterfaceAttribute(ClassInterfaceType.AutoDual)>]
type Object = class end
The Object type exposes the following members.

Remarks
Languages typically do not require a class to declare inheritance from Object because the inheritance is implicit.
Because all classes in the .NET Framework are derived from Object, every method defined in the Object class is available in all objects in the system. Derived classes can and do override some of these methods, including:
Equals - Supports comparisons between objects.
Finalize - Performs cleanup operations before an object is automatically reclaimed.
GetHashCode - Generates a number corresponding to the value of the object to support the use of a hash table.
ToString - Manufactures a human-readable text string that describes an instance of the class.
Performance Considerations
If you are designing a class, such as a collection, that must handle any type of object, you can create class members that accept instances of the Object class. However, the process of boxing and unboxing a type carries a performance cost. If you know your new class will frequently handle certain value types you can use one of two tactics to minimize the cost of boxing.
Create a general method that accepts an Object type, and a set of type-specific method overloads that accept each value type you expect your class to frequently handle. If a type-specific method exists that accepts the calling parameter type, no boxing occurs and the type-specific method is invoked. If there is no method argument that matches the calling parameter type, the parameter is boxed and the general method is invoked.
Design your type and its members to use generics. The common language runtime creates a closed generic type when you create an instance of your class and specify a generic type argument. The generic method is type-specific and can be invoked without boxing the calling parameter.
Although it is sometimes necessary to develop general purpose classes that accept and return Object types, you can improve performance by also providing a type-specific class to handle a frequently used type. For example, providing a class that is specific to setting and getting Boolean values eliminates the cost of boxing and unboxing Boolean values.

Examples
The following example defines a Point type derived from the Object class and overrides many of the virtual methods of the Object class. In addition, the example shows how to call many of the static and instance methods of the Object class.
Class Point
Public x, y As Integer
Public Sub New(ByVal x As Integer, ByVal y As Integer)
Me.x = x
Me.y = y
End Sub
Public Overrides Function Equals(ByVal obj As Object) As Boolean
Dim objType As Type = obj.GetType()
Dim meType As Type = Me.GetType()
If Not objType.Equals(meType) Then
Return False
End If
Dim other As Point = CType(obj, Point)
Return Me.x = other.x AndAlso Me.y = other.y
End Function
Public Overrides Function GetHashCode() As Integer
Return x XOr y
End Function
Public Overrides Function ToString() As String
Return String.Format("({0}, {1})", x, y)
End Function
Public Function Copy() As Point
Return CType(Me.MemberwiseClone(), Point)
End Function
End Class
NotInheritable Public Class App
Shared Sub Main()
Dim p1 As New Point(1, 2)
Dim p2 As Point = p1.Copy()
Dim p3 As Point = p1
Console.WriteLine([Object].ReferenceEquals(p1, p2))
Console.WriteLine([Object].Equals(p1, p2))
Console.WriteLine([Object].ReferenceEquals(p1, p3))
Console.WriteLine("p1's value is: {0}", p1.ToString())
End Sub
End Class
using System;
class Point
{
public int x, y;
public Point(int x, int y)
{
this.x = x;
this.y = y;
}
public override bool Equals(object obj)
{
if (obj.GetType() != this.GetType()) return false;
Point other = (Point) obj;
return (this.x == other.x) && (this.y == other.y);
}
public override int GetHashCode()
{
return x ^ y;
}
public override String ToString()
{
return String.Format("({0}, {1})", x, y);
}
public Point Copy()
{
return (Point) this.MemberwiseClone();
}
}
public sealed class App {
static void Main()
{
Point p1 = new Point(1,2);
Point p2 = p1.Copy();
Point p3 = p1;
Console.WriteLine(Object.ReferenceEquals(p1, p2));
Console.WriteLine(Object.Equals(p1, p2));
Console.WriteLine(Object.ReferenceEquals(p1, p3));
Console.WriteLine("p1's value is: {0}", p1.ToString());
}
}
using namespace System;
ref class Point
{
public:
int x;
public:
int y;
public:
Point(int x, int y)
{
this->x = x;
this->y = y;
}
public:
virtual bool Equals(Object^ obj) override
{
if (obj->GetType() != this->GetType())
{
return false;
}
Point^ other = (Point^) obj;
return (this->x == other->x) && (this->y == other->y);
}
public:
virtual int GetHashCode() override
{
return x ^ y;
}
public:
virtual String^ ToString() override
{
return String::Format("({0}, {1})", x, y);
}
public:
Point^ Copy()
{
return (Point^) this->MemberwiseClone();
}
};
int main()
{
Point^ p1 = gcnew Point(1, 2);
Point^ p2 = p1->Copy();
Point^ p3 = p1;
Console::WriteLine(
Object::ReferenceEquals(p1, p2));
Console::WriteLine(Object::Equals(p1, p2));
Console::WriteLine(Object::ReferenceEquals(p1, p3));
Console::WriteLine("p1's value is: {0}", p1->ToString());
}

Version Information
.NET Framework
Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0
.NET Framework Client Profile
Supported in: 4, 3.5 SP1
Portable Class Library
Supported in: Portable Class Library
.NET for Windows Store apps
Supported in: Windows 8

Platforms
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Thread Safety
Public static (Shared in Visual Basic) members of this type are thread safe. Instance members are not guaranteed to be thread-safe.

See Also