[問題] trace C++ 寫出result的考題

看板C_and_CPP (C/C++)作者hyujr (鬱)時間15年前 (2011/03/05 15:16)推噓0(0推 0噓 1→)

留言1則, 1人參與討論串1/2 (看更多)

因為本身只學過C語言也沒學得很深突然發現考題裡面有C++有點嚇到不過就硬頭皮把程式碼打下來邊想邊對照Output 後來做了幾份大概有些概念雖然也不確定到底思考的流程是不是對的= = 但有個地方實在想不通不知道有沒有人可以幫我說明一下.. # include <string> # include <iostream> class Base { public: Base(int b1 = 0, int b2 = 0) {value1 = b1; value2 = b2;} void compute(int x) {value1 += x; value2 *= x;} void compute1(int x) {calculate(x);} virtual void calculate(int x) {value1 = x; value2 = x * x;} void print() {cout << value1 + value2 << " ";} int value1, value2; }; class Derived: public Base { public: Derived(int x1, int x2, int x3):Base(x1, x2) {value2 = x1 + x2; value3 = x3;} virtual void calculate(int x) {value1 = x; value2 = 2 * x; value3 = x + 1;} void print() {cout << value2 + value3 << " ";} int value2, value3; }; void main() { Base b1(1, 2); b1.print(); b1.compute(3); b1.print(); Derived d1(2, 3, 4); d1.print(); d1.compute(5); d1.Base::print(); Derived d2(3, 4, 5); Base b2; b2 = d2; b2.print(); Derived d3(4, 5, 6); d3.calculate(3); d3.print(); d3.Base::print(); //這行 Derived d4(5, 6, 7); Base *b4; b4 = &d4; b4->compute(2); b4->print(); b4->calculate(4); d4.print(); Base *b5 = new Derived(6, 7, 8); b5->compute1(5); b5->print(); //這行 system("pause"); } 有標記那兩行的所輸出結果想不通有沒有人可以幫我說明一下~ 謝謝！ -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 114.24.182.89 ※ 編輯: hyujr 來自: 114.24.182.89 (03/05 15:19)