//Ví dụ minh họa nạp chồng toán tử (operator) ==, !=, + , - trong C# sử dụng implicit và explicit
using System;
public class Fraction{
publicFraction(int numerator, int denominator){
Console.WriteLine("In Fraction Constructor(int, int)");
this.numerator=numerator;
this.denominator=denominator;
}
publicFraction(int wholeNumber){
Console.WriteLine("In Fraction Constructor(int)");
numerator = wholeNumber;
denominator = 1;
}
public static implicit operator Fraction(inttheInt){
System.Console.WriteLine("In implicit conversion to Fraction");
return new Fraction(theInt);
}
public static explicit operator int(Fraction theFraction){
System.Console.WriteLine("In explicit conversion to int");
returntheFraction.numerator / theFraction.denominator;
}
public static bool operator==(Fraction lhs, Fraction rhs){
Console.WriteLine("In operator ==");
if(lhs.denominator == rhs.denominator &&
lhs.numerator == rhs.numerator)
{
return true;
}
// code here to handle unlike fractions
return false;
}
public static bool operator !=(Fraction lhs, Fraction rhs){
Console.WriteLine("In operator !=");
return!(lhs==rhs);
}
public override bool Equals(object o){
Console.WriteLine("In method Equals");
if (! (o is Fraction) ){
return false;
}
return this == (Fraction) o;
}
public static Fraction operator+(Fraction lhs, Fraction rhs){
Console.WriteLine("In operator+");
if(lhs.denominator == rhs.denominator){
return new Fraction(lhs.numerator+rhs.numerator,
lhs.denominator);
}
// simplistic solution for unlike fractions
// 1/2 + 3/4 == (1*4) + (3*2) / (2*4) == 10/8
intfirstProduct = lhs.numerator * rhs.denominator;
intsecondProduct = rhs.numerator * lhs.denominator;
return new Fraction(
firstProduct + secondProduct,
lhs.denominator * rhs.denominator
);
}
public override stringToString(){
String s = numerator.ToString( ) + "/" +
denominator.ToString( );
return s;
}
private int numerator;
private int denominator;
}
public class Tester{
static void Main(){
//implicit conversion to Fraction
Fraction f1 = newFraction(3);
Console.WriteLine("f1: {0}", f1.ToString( ));
Fraction f2 = newFraction(2,4);
Console.WriteLine("f2: {0}", f2.ToString( ));
Fraction f3 = f1 + f2;
Console.WriteLine("f1 + f2 = f3: {0}", f3.ToString());
Fraction f4 = f3 + 5;
Console.WriteLine("f3 + 5 = f4: {0}", f4.ToString());
Fraction f5 = newFraction(2,4);
if (f5 == f2){
Console.WriteLine("F5: {0} == F2: {1}", f5.ToString(),
f2.ToString());
}
int k = (int)f4; //explicit conversion to int
Console.WriteLine("int: F5 = {0}", k.ToString());
}
}
