类定义

#ifndef SIMPLECAlCULATOR_H
#define SIMPLECAlCULATOR_H
// class SimpleCalculator definition
class SimpleCalculator
{
public: 
   /* Write prototype for add member function */
    SimpleCalculator(double,double);
    void setDate(double, double);
    double adding(double, double) const;
   double subtract( double, double ) const; 
   double multiply( double, double ) const;
   double dividing(double, double) const;
   /* Write prototype for divide member function */
private:
    double a;
    double b;
}; // end class SimpleCalculator
#endif

函数(方法)

#include "SimpleCalculator.h"
/* Write definition for add member function */
// function subtract definition
SimpleCalculator::SimpleCalculator(double a,double b)
{
    setDate(a,b);
}
void SimpleCalculator::setDate(double one,double two)
{
    a = one;
    b = two;
}
double SimpleCalculator::adding(double a, double b) const
{
    return a + b;
}
double SimpleCalculator::subtract( double a, double b ) const
{
   return a - b;
} // end function subtract
// function multiply definition
double SimpleCalculator::multiply( double a, double b ) const
{
   return a * b;
} // end function multiply
double SimpleCalculator::dividing(double a, double b) const
{
    return a / b;
}
/* Write definition for divide member function */

主函数

#include 
using std::cout;
using std::endl;
#include "SimpleCalculator.h"
int main()
{
   double a = 10.0;
   double b = 20.0;
   SimpleCalculator sc(a, b);
   /* Instantiate an object of type Simplecalculator */
   cout << "The value of a is: " << a << "\n";
   cout << "The value of b is: " << b << "\n\n";
   /* Write a line that adds a and b through your SimpleCalculator
      object; assign the result to a variable named addition */
   double addition = sc.adding(a, b);
   cout << "Adding a and b yields " << addition << "\n";
   double subtraction = sc.subtract( a, b );
   cout << "Subtracting b from a yields " << subtraction << "\n";
   double multiplication = sc.multiply( a, b );
   cout << "Multiplying a and b yields " << multiplication << "\n";
   /* Write a line that divides a and b through the
      SimpleCalculator object; assign the result to a
      variable named division */
   double division = sc.dividing(a, b);
   cout << "Dividing a by b yields " << division << endl;
   return 0;
}