C++ examples for Class:Operator Overload
Overload insertion and extraction operator functions in the Complex class
#include <iostream> #include <string> using namespace std; // declaration section class Complex/*w w w . j av a 2s.c o m*/ { // prototypes for the overloaded operators friend ostream& operator<<(ostream&, const Complex&); friend istream& operator>>(istream&, Complex&); private: double realPart; double imaginaryPart; public: Complex(double real = 0.0, double imag = 0.0) // inline constructor { realPart = real; imaginaryPart = imag; } }; // overloaded insertion operator function ostream& operator<<(ostream& out, const Complex& num) { char sign = '+'; if (num.imaginaryPart < 0) sign = '-'; if (num.realPart == 0 && num.imaginaryPart == 0) cout << 0; else if (num.imaginaryPart == 0) cout << num.realPart; else if (num.realPart == 0) cout << num.imaginaryPart << 'i'; else cout << num.realPart << ' ' << sign << ' ' << abs(num.imaginaryPart) << 'i'; return out; } // overloaded extraction operator function istream& operator>>(istream& in, Complex& num) { string temp; double value; int plusLocation, minusLocation, i_Location; in >> value; // accept the first number getline(cin,temp); // input remaining characters entered, if any plusLocation = temp.find('+'); // find whether a + was entered minusLocation = temp.find('-'); // find whether a - was entered i_Location = temp.find('i'); // find whether an i was entered if (plusLocation >= 0 || minusLocation >= 0) { num.realPart = value; if (plusLocation >= 0) temp.replace(plusLocation,1," "); if (minusLocation >= 0) temp.replace(minusLocation,1," "); if (i_Location >= 0) temp.replace(i_Location,1," "); num.imaginaryPart = atof(temp.c_str()); // imaginary part if (minusLocation >= 0) num.imaginaryPart = -num.imaginaryPart; } else if (i_Location >= 0) // only an i follows the first value { num.realPart = 0.0; num.imaginaryPart = value; } else // no legitimate characters follow the first number { num.realPart = value; num.imaginaryPart = 0.0; } return in; } int main() { Complex complexOne; cout << "Enter a complex number (ex 3.2 + 7.4i): "; cin >> complexOne; // accept the complex number, using cin cout << "The complex number just entered is " << complexOne << endl; return 0; }