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 = 0;
    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 0;
}

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