C + + operator overloading

1. Operator overloading

• Assigning multiple meanings to an existing operator
• Produce different types of behavior when the same operator is acting on different types of data

Objective

• Extends the scope of the operators provided in C + + for use in the abstract data types represented by the class

The overloaded nature of an operator is a function overload with the following type:

operator operator (formal parameter list) {    ...    }

At program compile time

• Call to operator function with an expression that contains an operator
• Take the operand of an operator as an argument to an operator function
• Operator is overloaded multiple times, which operator function is called based on the type of the argument
• Operators can be overloaded into normal functions, or they can be overloaded into class member functions

Operator overloading is an example of a normal function:

#include <iostream>using namespacestd;classComplex { Public: Complex (DoubleR =0.0,Doublei =0.0) {Real=R; IMG=i; }    DoubleReal//Real part    Doubleimg//Imaginary part}; Complexoperator+ (ConstComplex &a,ConstComplex &b) {    returnComplex (A.real+b.real, a.img+b.img);}intMain () {Complex A (1,2), B (2,3), C; C= A +b; cout<< C.real <<":"<< c.img <<Endl;}

Here a+b is equivalent to operator+ (A, b);

When overloading as a normal function, the number of arguments is the count of operators.

Operator overloading is an example of a member function: (when overloaded to a member function, the number of arguments is one less operator)

#include <iostream>using namespacestd;classComplex { Public: Complex (DoubleR =0.0,Doublei =0.0) {Real=R; IMG=i; } Complexoperator+(ConstComplex &);//additionComplexoperator-(ConstComplex &);//Subtraction    DoubleReal//Real part    Doubleimg//Imaginary part}; Complex Complex::operator+(ConstComplex &Operand2) {    returnComplex (Real+operand2.real, img+operand2.img);} Complex Complex::operator-(ConstComplex &Operand2) {    returnComplex (Real-operand2.real, img-operand2.img);}intMain () {Complex A (1,2), B (2,3), C; C= A +b; cout<< C.real <<":"<< c.img <<Endl; C= B-A; cout<< C.real <<":"<< c.img <<Endl;}

C + + operator overloading