round

The difference between round C language and C++

Enter the radius to find the area;

C language

#include<stdio.h>
struct MyCicle
{
	double m_r;
	double m_s;
}c1;
intmain()
{
	printf("Enter the radius of the c1 circle:");
	scanf("%lf",&c1.m_r);
	printf("Output the area of ​​c1 circle:%4.2lf",3.14*c1.m_r*c1.m_r);
	return 0;
}

C++

#include<iostream>
using namespace std;
class MyCicle
{
	public:
		double m_r;//The radius of the circle
		double m_s;//Area of ​​the circle
	public:
		void setR(double r)//member function
		{
			m_r=r;
		}
		double getR()//member function
		{
			return m_r;
		}
		double getS()
		{
			m_s=3.14*m_r*m_r;
			return m_s;	
		}
};
// class abstraction
// instantiate
// find the area
//Procedure-oriented is a function one by one
//Object-oriented is a class one by one

// class call execution process
intmain()
{
	MyCicle c1,c2,c3;//Define variable objects with classes
	double r;
	cout<<"Please enter the radius of the c1 circle: ";
	cin>>r;
	//Assign the attribute of the c1 circle
	c1.setR(r);
	cout<<"The area of ​​the c1 element is: "<<c1.getS()<<endl;
	return 0;
}

Better understanding of process-oriented and object-oriented