TAILIEUCHUNG - Object Oriented Programming (10)
CSC241: Object Oriented Programming. Lecture No 10. 1 Previous Lecture.•. Example : Distance class. – overloading ++ and –. •. ++ add 1 in feet and 1 in inches,. •. -- subtract 1 from feet and 1 from inches. – Prefix and postfix.•. Overloading binary operator. d3= d1+d2;. Distance operator + (Distance d2) {. float i = inches + ;. int f = feet + ;. return Distance(f, i);. } 2 Today’s Lecture.•. Overloading binary operator. –. +, – and = operator for ThreeD class. –. < operator for distance class. –. += operator for distance class. –. Subscript operator [] for Safe array class.•. Data conversion. 3 Overloading -, + and = ThreeD { Operators. // Overload subtraction int x, y, z; ThreeD ThreeD::operator-. (ThreeD op2) {.public: ThreeD temp;. ThreeD() { x = y = z = 0; } = x - ;. ThreeD(int i, int j, int k) = y - ;. { x = i; y = j; z = k; } = z - ;. ThreeD operator+ return temp;. }.(ThreeD op2); // Overload + ThreeD operator=(ThreeD op ThreeD ThreeD::operator+.2); (ThreeD op2) {. ThreeD operator- ThreeD temp;.(ThreeD op2); = x + ;. = y + ;. void show() ; = z + ;.}; return temp;. }. 4 Cont// Overload assignment. main() {.ThreeD ThreeD::operator=(ThreeD ThreeD a(1, 2, 3), b(10, 10, ){. x = ;. ), c;. y = ; cout << "Original value of a:. z = ; ";. return *this; ();.}.void ThreeD::show() {. cout << x << ", ”<< y << ", ”<< z <<. cout << "Original value of b: ". "\n"; ;.} ();. c = b - a;.PROGRAM OUTPUT: cout << “b - a: ";.Original value of a: 1, 2, 3 ();.Original value of b: 10, 10, 10 }.b - a: 9, 8, 7 5 Multiple Overloading.•. We’ve seen different uses of the + operator: to. add distances and to concatenate strings•. You could put both these classes together in the. same program, and C++ would still know how to. interpret the + operator:. – d1 = d2 + d3;. – s1 = s2 + s3;.•. It selects the correct function to carry out the. “addition” based on the type of operand 6 Comparison Operator <. Main function. Distance dist1(3, );. Distance dist2(6, );. if( dist1 < dist2 ). cout << “\ndist1 is less than dist2”;. else. cout << “\ndist1 is greater than (or equal to). dist2”;.bool Distance::operator < (Distance d2).const {. float bf1 = feet + inches/12;. float bf2 = + ;. return (bf1 < bf2) ? true : false; Go to program.}. 7 Arithmetic assignment: Operator +=. Main() function. Distance dist1(3, );. Distance dist2(5 )
đang nạp các trang xem trước
