C #: sobrecarga del operador
Puede redefinir o sobrecargar la mayoría de los operadores integrados disponibles en C #. Por tanto, un programador también puede utilizar operadores con tipos definidos por el usuario. Los operadores sobrecargados son funciones con nombres especiales la palabra claveoperatorseguido del símbolo del operador que se está definiendo. similar a cualquier otra función, un operador sobrecargado tiene un tipo de retorno y una lista de parámetros.
Por ejemplo, vaya a la siguiente función:
public static Box operator+ (Box b, Box c) {
Box box = new Box();
box.length = b.length + c.length;
box.breadth = b.breadth + c.breadth;
box.height = b.height + c.height;
return box;
}
La función anterior implementa el operador de suma (+) para una clase Box definida por el usuario. Agrega los atributos de dos objetos Box y devuelve el objeto Box resultante.
Implementación de la sobrecarga del operador
El siguiente programa muestra la implementación completa:
using System;
namespace OperatorOvlApplication {
class Box {
private double length; // Length of a box
private double breadth; // Breadth of a box
private double height; // Height of a box
public double getVolume() {
return length * breadth * height;
}
public void setLength( double len ) {
length = len;
}
public void setBreadth( double bre ) {
breadth = bre;
}
public void setHeight( double hei ) {
height = hei;
}
// Overload + operator to add two Box objects.
public static Box operator+ (Box b, Box c) {
Box box = new Box();
box.length = b.length + c.length;
box.breadth = b.breadth + c.breadth;
box.height = b.height + c.height;
return box;
}
}
class Tester {
static void Main(string[] args) {
Box Box1 = new Box(); // Declare Box1 of type Box
Box Box2 = new Box(); // Declare Box2 of type Box
Box Box3 = new Box(); // Declare Box3 of type Box
double volume = 0.0; // Store the volume of a box here
// box 1 specification
Box1.setLength(6.0);
Box1.setBreadth(7.0);
Box1.setHeight(5.0);
// box 2 specification
Box2.setLength(12.0);
Box2.setBreadth(13.0);
Box2.setHeight(10.0);
// volume of box 1
volume = Box1.getVolume();
Console.WriteLine("Volume of Box1 : {0}", volume);
// volume of box 2
volume = Box2.getVolume();
Console.WriteLine("Volume of Box2 : {0}", volume);
// Add two object as follows:
Box3 = Box1 + Box2;
// volume of box 3
volume = Box3.getVolume();
Console.WriteLine("Volume of Box3 : {0}", volume);
Console.ReadKey();
}
}
}
Cuando se compila y ejecuta el código anterior, produce el siguiente resultado:
Volume of Box1 : 210
Volume of Box2 : 1560
Volume of Box3 : 5400
Operadores que se pueden sobrecargar y no se pueden sobrecargar
La siguiente tabla describe la capacidad de sobrecarga de los operadores en C # -
No Señor. | Operadores y descripción |
---|---|
1 | +, -, !, ~, ++, -- Estos operadores unarios toman un operando y pueden sobrecargarse. |
2 | +, -, *, /, % Estos operadores binarios toman un operando y pueden sobrecargarse. |
3 | ==, !=, <, >, <=, >= Los operadores de comparación pueden estar sobrecargados. |
4 | &&, || Los operadores lógicos condicionales no se pueden sobrecargar directamente. |
5 | +=, -=, *=, /=, %= Los operadores de asignación no se pueden sobrecargar. |
6 | =, ., ?:, ->, new, is, sizeof, typeof Estos operadores no se pueden sobrecargar. |
Ejemplo
A la luz de las discusiones anteriores, extendamos el ejemplo anterior y sobrecarguemos algunos operadores más:
using System;
namespace OperatorOvlApplication {
class Box {
private double length; // Length of a box
private double breadth; // Breadth of a box
private double height; // Height of a box
public double getVolume() {
return length * breadth * height;
}
public void setLength( double len ) {
length = len;
}
public void setBreadth( double bre ) {
breadth = bre;
}
public void setHeight( double hei ) {
height = hei;
}
// Overload + operator to add two Box objects.
public static Box operator+ (Box b, Box c) {
Box box = new Box();
box.length = b.length + c.length;
box.breadth = b.breadth + c.breadth;
box.height = b.height + c.height;
return box;
}
public static bool operator == (Box lhs, Box rhs) {
bool status = false;
if (lhs.length == rhs.length && lhs.height == rhs.height
&& lhs.breadth == rhs.breadth) {
status = true;
}
return status;
}
public static bool operator !=(Box lhs, Box rhs) {
bool status = false;
if (lhs.length != rhs.length || lhs.height != rhs.height ||
lhs.breadth != rhs.breadth) {
status = true;
}
return status;
}
public static bool operator <(Box lhs, Box rhs) {
bool status = false;
if (lhs.length < rhs.length && lhs.height < rhs.height
&& lhs.breadth < rhs.breadth) {
status = true;
}
return status;
}
public static bool operator >(Box lhs, Box rhs) {
bool status = false;
if (lhs.length > rhs.length && lhs.height >
rhs.height && lhs.breadth > rhs.breadth) {
status = true;
}
return status;
}
public static bool operator <=(Box lhs, Box rhs) {
bool status = false;
if (lhs.length <= rhs.length && lhs.height
<= rhs.height && lhs.breadth <= rhs.breadth) {
status = true;
}
return status;
}
public static bool operator >=(Box lhs, Box rhs) {
bool status = false;
if (lhs.length >= rhs.length && lhs.height
>= rhs.height && lhs.breadth >= rhs.breadth) {
status = true;
}
return status;
}
public override string ToString() {
return String.Format("({0}, {1}, {2})", length, breadth, height);
}
}
class Tester {
static void Main(string[] args) {
Box Box1 = new Box(); // Declare Box1 of type Box
Box Box2 = new Box(); // Declare Box2 of type Box
Box Box3 = new Box(); // Declare Box3 of type Box
Box Box4 = new Box();
double volume = 0.0; // Store the volume of a box here
// box 1 specification
Box1.setLength(6.0);
Box1.setBreadth(7.0);
Box1.setHeight(5.0);
// box 2 specification
Box2.setLength(12.0);
Box2.setBreadth(13.0);
Box2.setHeight(10.0);
//displaying the Boxes using the overloaded ToString():
Console.WriteLine("Box 1: {0}", Box1.ToString());
Console.WriteLine("Box 2: {0}", Box2.ToString());
// volume of box 1
volume = Box1.getVolume();
Console.WriteLine("Volume of Box1 : {0}", volume);
// volume of box 2
volume = Box2.getVolume();
Console.WriteLine("Volume of Box2 : {0}", volume);
// Add two object as follows:
Box3 = Box1 + Box2;
Console.WriteLine("Box 3: {0}", Box3.ToString());
// volume of box 3
volume = Box3.getVolume();
Console.WriteLine("Volume of Box3 : {0}", volume);
//comparing the boxes
if (Box1 > Box2)
Console.WriteLine("Box1 is greater than Box2");
else
Console.WriteLine("Box1 is not greater than Box2");
if (Box1 < Box2)
Console.WriteLine("Box1 is less than Box2");
else
Console.WriteLine("Box1 is not less than Box2");
if (Box1 >= Box2)
Console.WriteLine("Box1 is greater or equal to Box2");
else
Console.WriteLine("Box1 is not greater or equal to Box2");
if (Box1 <= Box2)
Console.WriteLine("Box1 is less or equal to Box2");
else
Console.WriteLine("Box1 is not less or equal to Box2");
if (Box1 != Box2)
Console.WriteLine("Box1 is not equal to Box2");
else
Console.WriteLine("Box1 is not greater or equal to Box2");
Box4 = Box3;
if (Box3 == Box4)
Console.WriteLine("Box3 is equal to Box4");
else
Console.WriteLine("Box3 is not equal to Box4");
Console.ReadKey();
}
}
}
Cuando se compila y ejecuta el código anterior, produce el siguiente resultado:
Box 1: (6, 7, 5)
Box 2: (12, 13, 10)
Volume of Box1 : 210
Volume of Box2 : 1560
Box 3: (18, 20, 15)
Volume of Box3 : 5400
Box1 is not greater than Box2
Box1 is less than Box2
Box1 is not greater or equal to Box2
Box1 is less or equal to Box2
Box1 is not equal to Box2
Box3 is equal to Box4