實例一、四位運算符操作

main.cpp.

 1 #include <iostream>
 2 #include "operator_1.h"
 3 #include <stdio.h>
 4 #include <iomanip>
 5 
 6 using namespace std;
 7 
 8 int main()
 9 {
10     double r = 0;
11     operator_1 op;
12 
13     op.setOperator_1(‘*‘);
14     op.setOperator_1Parameter(100.0, 3.0
 
);
15 
16     if (op.result(r)){
17         cout<<setiosflags(ios::fixed)<<r<<endl;//位數不夠，末尾添0
18     }
19     else {
20         cout <<"calculate erro!" << endl;
21     }
22 
23     return 0;
24 }

operator_1.cpp

 1 #include "operator_1.h"
 2 
 3 bool operator_1::setOperator_1(char
 
 op){
 4     bool ret = false;
 5     if((op == ‘*‘)||(op == ‘/‘)||( op == ‘+‘)||( op == ‘*‘)){
 6         ret == true;
 7         op_1 =op;
 8     }
 9     else {
10         return ret;
11     }
12 }
13 
14 void operator_1::setOperator_1Parameter(double a, double b){
15     m0p = a;
16     m1p = b;
17
 
 }
18 
19 bool operator_1::result(double & r){
20     bool ret = true;
21     switch (op_1) {
22     case ‘+‘:
23         r = m0p + m1p;
24         break;
25     case ‘-‘:
26         r = m0p - m1p;
27         break;
28     case ‘*‘:
29         r = m0p * m1p;
30         break;
31     case ‘/‘:
32         r = m0p / m1p;
33         break;
34     default:
35         return ret= false;
36         break;
37     }
38 }

operator_1.h

 1 #ifndef OPERATOR_H
 2 #define OPERATOR_H
 3 
 4 class operator_1
 5 {
 6 public:
 7     bool setOperator_1(char op);
 8     void setOperator_1Parameter(double a, double b);
 9     bool result(double & r);
10 private:
11     double m0p;
12     double m1p;
13     char op_1;
14 };
15 #endif // OPERATOR_H

C++面向對象編程實例