Function OverloadingSquare functionUse overloaded functionFriend function and friend classDeclare a function as friendFriendshipExampleExample continueUse this pointerPowerPoint PresentationSlide 11Operator OverloadingCan we make Complex class easier to use as follow?Yes, Overload the operatorsWhere to define overloading operatorImplementationOverload operator >>implementationFunction OverloadingCan enables several functionOf same nameOf different sets of parameters (at least as far as their types are concerned)Used to create several functions of the same name that perform similar tasks but on different data typesSquare functionint square(int x){ return x*x; }double square(double y){ return y*y;}float square(float z){ return z*z;}Use overloaded functionComplier will search for the match function prototypeint main(){ int x=7; double y=7.5; cout<<“square of “<<x<<“ is “ <<square(x)<<endl; cout<<“Square of “<<y<<“is “ <<square(y)<<endl;}Friend function and friend classA friend function of a class is defined outside that class scopeHas right to access private members of the classUsing friend functions can enhance performanceOften appropriate when a member function cannot be used for certain operationsDeclare a function as friend To declare a function as a friend of a class, precede the function prototype in class definition with key word friendTo declare a class Two as a friend of One, place friend class Two; in the definition of class OneFriendshipFriendship is granted, not takenFriendship is not symmetricIf B is friend of A, I.e. A declared B as friend, you cannot infer A is friend of B unless B declare A as friendFriendship is not transitiveA is friend of B, and B is friend of C, you cannot say that A is friend of CExample class Count{ friend void setX(Count &, int); public: Count(){x=0;} void print() const {cout<<x<<endl;} private: int x;};Example continuevoid setX(Count &c, int val){ c.x = val;}int main(){ Count counter;counter.print();setX(counter, 8);return 0;}Use this pointerEvery object has access to its own address through a pointer called thisThis pointer is not part of objectThis pointer is passed into object (by compiler) as implicit first argument on every non-static member functionclass Test{int x;public:Test( int =0);void print() const;};Test::test(int a){ x = a;}void Test::print() const{ cout<<“ x = “<<x <<“\nthis->x = “<<this->x <<“\n(*this).x = “<<(*this).x <<endl;}int main(){ Test t(12); t.print(); return 0;}x = 12this->x = 12(*this).x = 12Output:Operator OverloadingEnable C++’s operators to work with class object<<, >>, +, -, *, / This operators perform differently depending on their context in integer, floatingThese operators are overloadedC++ allow programmer to overload most operatorsCan we make Complex class easier to use as follow?int main(){ Complex x,y,z; cout<<“Type in two complex numbers\n”; cin>>x >>y; z = x + y; cout<< x <<“+” <<y<<“=“ <<z<<endl;}Type in two complex numbers(2,3)(3,4)(2,3) + (3,4) = (5,7)Yes, Overload the operatorsOperator are overloaded by writing a function definition( header and body)Function name become the keyword operator followed by the symbol for the operator being overloaded operator+ would be used to overload the addition operator(+)Precedence and associativity of an operator cannot be changed by overloadingWhere to define overloading operatorAs non member functionMust be friend of the classSo it is in class definitionclass Complex{ friend ostream& operator<<(ostream&, const Complex &); ...}Function nameReturn typeparametersImplementationostream & operator<<(ostream & out, const Complex &c){ out<<“(“<<c.real<<“,”<<c.img<<“)”; return out; // enables cout<<x<<y;}Overload operator >>In class definition class Complex { friend ostream& operator<< (ostream &, const Complex &); friend istream& operator>> (istream&, Complex &);...}implementationistream & operator>>( istream & input,Complex & c){ input.ignore(); input>>c.real; input.ignore(); input>>c.img; input.ignore(); return