实现简单的计算器（计算功能模块实现）

#ifndef EXECUTE_H
#define EXECUTE_H
#include <QString>

class execute
{
public:
    execute();
    void setnum1(int num);
    void setnum2(int num);
    void setflag(QString flag);
    QString doexe();
private:
    int num1;
    int num2;
    QString flag;
};

#endif // EXECUTE_H

#include "execute.h"

execute::execute()
{
    num1=0;
    num2=0;
}

void execute::setnum1(int num){
    this->num1 = num;
}

void execute::setnum2(int num){
    this->num2 = num;
}

void execute::setflag(QString flag){
    this->flag = flag;
}

QString execute::doexe(){
    int result = 0;
    if(this->flag == "+"){
        result = this->num1+this->num2;
    }else if (this->flag == "-") {
        result = this->num1-this->num2;
    }else if (this->flag == "*") {
        result = this->num1*this->num2;
    }else if (this->flag == "/") {
        if(this->num2 == 0){
            return "ERROR";
        }else {
            result = this->num1*this->num2;
        }
    }else {
        result = this->num1;
    }
    return QString::number(result);
}