类的基本用法

twoobj.cpp code:

// example: one class, two objects
#include <iostream>
using namespace std;

class CRectangle {
    int x, y;
  public:
    void set_values (int,int);
    int area () {return (x*y);}
};

void CRectangle::set_values (int a, int b) {
  x = a;
  y = b;
}

int main () {
  CRectangle rect, rectb;
  rect.set_values (3,4);
  rectb.set_values (5,6);
  cout << "rect area: " << rect.area() << endl;
  cout << "rectb area: " << rectb.area() << endl;
  return 0;
}

Makefile:
all:
 g++ -o main twoobj.cpp
 ./main
 

结果：
[root@google Cpp]# make
g++ -o main twoobj.cpp
./main
rect area: 12
rectb area: 30