C++与C语言最大的不同在于:
C++的数据和函数封装在一起,因此无需参数传递数据!
下面看一个计算圆形面积的程序:
#include <iostream>
using namespace std;
class Circle {
public:
double radius;
Circle()
{
radius = 1;
}
Circle(double newRadius)
{
radius = newRadius;
}
double getArea() {//无形参,直接访问成员,与C语言最大的不同
return radius * radius * 3.14159;
}
};
int main() {
Circle circle1;
Circle circle2(5.0);
cout << "The area of the circle of radius " <<
circle1.radius << " is " << circle1.getArea() << endl;
cout << "The area of the circle of radius " <<
circle2.radius << " is " << circle2.getArea() << endl;
// Modify circle radius
circle2.radius = 100.0;
cout << "The area of the circle of radius " <<
circle2.radius << " is " << circle2.getArea() << endl;
return 0;
}