C++面向对象编程实例

实例一、四位运算符操作

main.cpp.

 #include <iostream>
 #include "operator_1.h"
 #include <stdio.h>
 #include <iomanip>

 using namespace std;

 int main()
 {
     double r = ;
     operator_1 op;

     op.setOperator_1('*');
     op.setOperator_1Parameter(100.0, 3.0);

     if (op.result(r)){
         cout<<setiosflags(ios::fixed)<<r<<endl;//位数不够，末尾添0
     }
     else {
         cout <<"calculate erro!" << endl;
     }

     return ;
 }

operator_1.cpp

 #include "operator_1.h"

 bool operator_1::setOperator_1(char op){
     bool ret = false;
     if((op == '*')||(op == '/')||( op == '+')||( op == '*')){
         ret == true;
         op_1 =op;
     }
     else {
         return ret;
     }
 }

 void operator_1::setOperator_1Parameter(double a, double b){
     m0p = a;
     m1p = b;
 }

 bool operator_1::result(double & r){
     bool ret = true;
     switch (op_1) {
     case '+':
         r = m0p + m1p;
         break;
     case '-':
         r = m0p - m1p;
         break;
     case '*':
         r = m0p * m1p;
         break;
     case '/':
         r = m0p / m1p;
         break;
     default:
         return ret= false;
         break;
     }
 }

operator_1.h

 #ifndef OPERATOR_H
 #define OPERATOR_H

 class operator_1
 {
 public:
     bool setOperator_1(char op);
     void setOperator_1Parameter(double a, double b);
     bool result(double & r);
 private:
     double m0p;
     double m1p;
     char op_1;
 };
 #endif // OPERATOR_H