Object.Equals 메서드 (Object) (System)

Imports System
Imports System.IO

Class Program
    Public Shared Sub Main(ByVal args As String())
        Dim Obj1 As New Object()
        Dim Obj2 As New Object()
        Console.WriteLine(Obj1.Equals(Obj2))
        Obj2 = Obj1
        Console.WriteLine(Obj1.Equals(Obj2))
    End Sub
End Class

'This example produces the following output:
'False
'True

using System;
class Program
{
    static void Main(string[] args)
    {
        Object Obj1 = new Object();
        Object Obj2 = new Object();
        Console.WriteLine(Obj1.Equals(Obj2));
        Obj2 = Obj1;
        Console.WriteLine(Obj1.Equals(Obj2)); 
    }
}

/* This example produces the following output:
False
True
 */

using namespace System;

void main()
{
    Object^ Obj1 = gcnew Object;
    Object^ Obj2 = gcnew Object;
    Console::WriteLine(Obj1->Equals(Obj2));
    Obj2 = Obj1;
    Console::WriteLine(Obj1->Equals(Obj2));
};

/* This example produces the following output:

False
True
 */

Imports System

Class Point
    Inherits Object
    Protected x, y As Integer

    Public Sub New() 
        Me.x = 0
        Me.y = 0
    End Sub 'New

    Public Sub New(ByVal X As Integer, ByVal Y As Integer) 
        Me.x = X
        Me.y = Y
    End Sub 'New

    Public Overrides Function Equals(ByVal obj As Object) As Boolean 
        'Check for null and compare run-time types.
        If obj Is Nothing OrElse Not [GetType]().Equals(obj.GetType()) Then
            Return False
        End If
        Dim p As Point = CType(obj, Point)
        Return x = p.x AndAlso y = p.y
    End Function 'Equals

    Public Overrides Function GetHashCode() As Integer 
        Return x ^ y
    End Function 'GetHashCode
End Class 'Point

Class Point3D
    Inherits Point
    Private z As Integer

    Public Sub New(ByVal X As Integer, ByVal Y As Integer, ByVal Z As Integer) 
        Me.x = X
        Me.y = Y
        Me.z = Z
    End Sub 'New

    Public Overrides Function Equals(ByVal obj As Object) As Boolean 
        Return MyBase.Equals(obj) AndAlso z = CType(obj, Point3D).z
    End Function 'Equals

    Public Overrides Function GetHashCode() As Integer 
        Return MyBase.GetHashCode() ^ z
    End Function 'GetHashCode
End Class 'Point3D

Class [MyClass]
    Public Shared Sub Main() 
        Dim point2D As New Point(5, 5)
        Dim point3Da As New Point3D(5, 5, 2)
        Dim point3Db As New Point3D(5, 5, 2)

        If Not point2D.Equals(point3Da) Then
            Console.WriteLine("point2D does not equal point3Da.")
        End If
        If Not point3Db.Equals(point2D) Then
            Console.WriteLine("Likewise, point3Db does not equal point2D.")
        End If
        If point3Da.Equals(point3Db) Then
            Console.WriteLine("However, point3Da equals point3Db.")
        End If

    End Sub 'Main 
End Class '[MyClass]
' ----------------------------------
' Output should be:
' 
' point2D does not equal point3Da.
' Likewise, point3Db does not equal point2D.
' However, point3Da equals point3Db.

using System;

class Point: Object {
   protected int x, y;

   public Point() {
     this.x = 0;
     this.y = 0;
   }

   public Point(int X, int Y) {
      this.x = X;
      this.y = Y;
   }

   public override bool Equals(Object obj) {
      //Check for null and compare run-time types.
      if (obj == null || GetType() != obj.GetType()) return false;
      Point p = (Point)obj;
      return (x == p.x) && (y == p.y);
   }

   public override int GetHashCode() {
      return x ^ y;
   }
}


class Point3D: Point {
   int z;

   public Point3D(int X, int Y, int Z) {
      this.x = X;
      this.y = Y;
      this.z = Z; 
   }

   public override bool Equals(Object obj) {
      return base.Equals(obj) && z == ((Point3D)obj).z;
   }

   public override int GetHashCode() {
      return base.GetHashCode() ^ z;
   }
}

class MyClass {

  public static void Main() {
     Point point2D = new Point(5, 5);
     Point3D point3Da = new Point3D(5, 5, 2);
     Point3D point3Db = new Point3D(5, 5, 2);

     if (!point2D.Equals(point3Da)) {
        Console.WriteLine("point2D does not equal point3Da.");
     }
     if (!point3Db.Equals(point2D)) {
        Console.WriteLine("Likewise, point3Db does not equal point2D.");
     }
     if (point3Da.Equals(point3Db)) {
        Console.WriteLine("However, point3Da equals point3Db.");
     }

  } 
}
// ----------------------------------
// Output should be:
// 
// point2D does not equal point3Da.
// Likewise, point3Db does not equal point2D.
// However, point3Da equals point3Db.

using namespace System;
ref class Point: public Object
{
protected:
   int x;
   int y;

public:
   Point()
   {
      this->x = 0;
      this->y = 0;
   }

   Point( int X, int Y )
   {
      this->x = X;
      this->y = Y;
   }

   virtual bool Equals( Object^ obj ) override
   {

      //Check for null and compare run-time types.
      if ( obj == nullptr || GetType() != obj->GetType() )
            return false;

      Point ^ p = dynamic_cast<Point^>(obj);
      return (x == p->x) && (y == p->y);
   }

   virtual int GetHashCode() override
   {
      return x ^ y;
   }

};

ref class Point3D: public Point
{
private:
   int z;

public:
   Point3D( int X, int Y, int Z )
   {
      this->x = X;
      this->y = Y;
      this->z = Z;
   }

   virtual bool Equals( Object^ obj ) override
   {
      return Point::Equals( obj ) && z == (dynamic_cast<Point3D^>(obj))->z;
   }

   virtual int GetHashCode() override
   {
      return Point::GetHashCode() ^ z;
   }

};

Imports System

Class Rectangle
    Private a, b As Point

    Public Sub New(ByVal upLeftX As Integer, ByVal upLeftY As Integer, _
                   ByVal downRightX As Integer, ByVal downRightY As Integer) 
        Me.a = New Point(upLeftX, upLeftY)
        Me.b = New Point(downRightX, downRightY)
    End Sub 'New

    Public Overrides Function Equals(ByVal obj As [Object]) As Boolean 
        ' Performs an equality check on two rectangles (Point object pairs).
        If obj Is Nothing OrElse Not [GetType]().Equals(obj.GetType()) Then
            Return False
        End If
        Dim r As Rectangle = CType(obj, Rectangle)
        'Uses Equals to compare variables.
        Return a.Equals(r.a) AndAlso b.Equals(r.b)
    End Function 'Equals

    Public Overrides Function GetHashCode() As Integer 
        Return a.GetHashCode() ^ b.GetHashCode()
    End Function 'GetHashCode
End Class 'Rectangle

' Class Point added for clean compile

Class Point
    Private x As Integer
    Private y As Integer

    Public Sub New(ByVal X As Integer, ByVal Y As Integer) 
        Me.x = X
        Me.y = Y
    End Sub 'New

    Public Overrides Function Equals(ByVal obj As [Object]) As Boolean 
        ' Performs an equality check on two points (integer pairs).
        If obj Is Nothing OrElse Not [GetType]().Equals(obj.GetType()) Then
            Return False
        End If
        Dim p As Point = CType(obj, Point)
        Return x = p.x AndAlso y = p.y

    End Function 'Equals

    Public Overrides Function GetHashCode() As Integer 
        Return x.GetHashCode() ^ y.GetHashCode()
    End Function 'GetHashCode
End Class 'Point 


Class [MyClass]
    Public Shared Sub Main() 
        Dim r1 As New Rectangle(0, 0, 100, 200)
        Dim r2 As New Rectangle(0, 0, 100, 200)
        Dim r3 As New Rectangle(0, 0, 150, 200)

        If r1.Equals(r2) Then
            Console.WriteLine("Rectangle r1 equals rectangle r2!")
        End If
        If Not r2.Equals(r3) Then
            Console.WriteLine("But rectangle r2 does not equal rectangle r3.")
        End If
    End Sub 'Main
End Class '[MyClass]
' ------------------------------
' Output should be:
' Rectangle r1 equals rectangle r2!
' But rectangle r2 does not equal rectangle r3.

using System;

class Rectangle {
   Point a, b;

   public Rectangle(int upLeftX, int upLeftY, int downRightX, int downRightY) {
      this.a = new Point(upLeftX, upLeftY);
      this.b = new Point(downRightX, downRightY);
   }

   public override bool Equals(Object obj) {
     // Performs an equality check on two rectangles (Point object pairs).
      if (obj == null || GetType() != obj.GetType()) return false;
      Rectangle r = (Rectangle)obj;
      //Uses Equals to compare variables.
      return a.Equals(r.a) && b.Equals(r.b);
   }

   public override int GetHashCode() {
      return a.GetHashCode() ^ b.GetHashCode();
   }
}

// Class Point added for clean compile
class Point {
  private int x;
  private int y;

  public Point(int X, int Y) {
     this.x = X;
     this.y = Y;
  }

  public override bool Equals (Object obj) {
     // Performs an equality check on two points (integer pairs).
     if (obj == null || GetType() != obj.GetType()) return false;
     Point p = (Point)obj;
     return (x == p.x) && (y == p.y);
  }

  public override int GetHashCode() {
     return x.GetHashCode() ^ y.GetHashCode();
  }

}

class MyClass {
   public static void Main() {

      Rectangle r1 = new Rectangle(0, 0, 100, 200);
      Rectangle r2 = new Rectangle(0, 0, 100, 200);
      Rectangle r3 = new Rectangle(0, 0, 150, 200);

      if (r1.Equals(r2)) {
         Console.WriteLine("Rectangle r1 equals rectangle r2!");
      }
      if (!r2.Equals(r3)) {
         Console.WriteLine("But rectangle r2 does not equal rectangle r3.");
      }
   }
}
// ------------------------------
// Output should be:
// Rectangle r1 equals rectangle r2!
// But rectangle r2 does not equal rectangle r3.

ref class Rectangle
{
private:
   Point^ a;
   Point^ b;

public:
   Rectangle( int upLeftX, int upLeftY, int downRightX, int downRightY )
   {
      this->a = gcnew Point( upLeftX,upLeftY );
      this->b = gcnew Point( downRightX,downRightY );
   }

   virtual bool Equals( Object^ obj ) override
   {

      // Performs an equality check on two rectangles (Point object pairs).
      if ( obj == nullptr || GetType() != obj->GetType() )
            return false;

      Rectangle^ r = dynamic_cast<Rectangle^>(obj);

      //Uses Equals to compare variables.
      return a->Equals( r->a ) && b->Equals( r->b );
   }

   virtual int GetHashCode() override
   {
      return a->GetHashCode() ^ b->GetHashCode();
   }

};

Public Structure Complex
    Public re, im As Double

    Public Overrides Function Equals(ByVal obj As [Object]) As Boolean 
        Return TypeOf obj Is Complex AndAlso Me = CType(obj, Complex)
    End Function 

    Public Overrides Function GetHashCode() As Integer 
        Return re.GetHashCode() ^ im.GetHashCode()
    End Function 

    Public Shared Operator = (x As Complex, y As Complex) As Boolean
       Return x.re = y.re AndAlso x.im = y.im
    End Operator 

    Public Shared Operator <> (x As Complex, y As Complex) As Boolean
       Return Not (x = y)
    End Operator  
End Structure

Class Example
   Public Shared Sub Main() 
      Dim cmplx1, cmplx2 As Complex

      cmplx1.re = 4.0
      cmplx1.im = 1.0

      cmplx2.re = 2.0
      cmplx2.im = 1.0

      If cmplx1 <> cmplx2 Then
         Console.WriteLine("The two objects are not equal.")
      End If
      If Not cmplx1.Equals(cmplx2) Then
         Console.WriteLine("The two objects are not equal.")
      End If

      cmplx2.re = 4.0

      If cmplx1.Equals(cmplx2) Then
         Console.WriteLine("The two objects are now equal!")
      End If
      If cmplx1 = cmplx2 Then
         Console.WriteLine("The two objects are now equal!")
      End If
   End Sub
End Class 
' The example displays the following output:
'       The two objects are not equal.
'       The two objects are not equal.
'       The two objects are now equal!
'       The two objects are now equal!

using System;

public struct Complex {
   public double re, im;

   public override bool Equals(Object obj) {
      return obj is Complex && this == (Complex)obj;
   }

   public override int GetHashCode() {
      return re.GetHashCode() ^ im.GetHashCode();
   }

   public static bool operator ==(Complex x, Complex y) {
      return x.re == y.re && x.im == y.im;
   }

   public static bool operator !=(Complex x, Complex y) {
      return !(x == y);
   }
}

class MyClass {

  public static void Main() {
    Complex cmplx1, cmplx2;

    cmplx1.re = 4.0;
    cmplx1.im = 1.0;

    cmplx2.re = 2.0;
    cmplx2.im = 1.0;

    if (cmplx1 != cmplx2)
      Console.WriteLine("The two objects are not equal.");
    if (! cmplx1.Equals(cmplx2))
      Console.WriteLine("The two objects are not equal.");

    cmplx2.re = 4.0;

    if (cmplx1 == cmplx2) 
      Console.WriteLine("The two objects are now equal!");
    if (cmplx1.Equals(cmplx2)) 
      Console.WriteLine("The two objects are now equal!");
  }
}
// The example displays the following output:
//       The two objects are not equal.
//       The two objects are not equal.
//       The two objects are now equal!
//       The two objects are now equal!

using namespace System;
public value struct Complex
{
public:
   double re;
   double im;
   virtual bool Equals( Object^ obj ) override
   {
      return (dynamic_cast<Complex^>(obj) != nullptr) && (*this == *dynamic_cast<Complex^>(obj));
   }

   virtual int GetHashCode() override
   {
      return re.GetHashCode() ^ im.GetHashCode();
   }

   static bool operator==( Complex x, Complex y )
   {
      return x.re == y.re && x.im == y.im;
   }

   static bool operator!=( Complex x, Complex y )
   {
      return  !(x == y);
   }
};

int main()
{
   Complex cmplx1;
   Complex cmplx2;
   cmplx1.re = 4.0;
   cmplx1.im = 1.0;
   cmplx2.re = 2.0;
   cmplx2.im = 1.0;
   if (cmplx1 != cmplx2)
      Console::WriteLine( "The two objects are not equal." );
   if (!(cmplx1.Equals(cmplx2)))
      Console::WriteLine( "The two objects are not equal." );

   cmplx2.re = 4.0;
   if (cmplx1 == cmplx2 )
      Console::WriteLine( "The two objects are now equal!" );
   if (cmplx1.Equals(cmplx2))
      Console::WriteLine( "The two objects are now equal!" );
}
// The example displays the following output:
//       The two objects are not equal.
//       The two objects are not equal.
//       The two objects are now equal!
//       The two objects are now equal!