用Xcode来写C++程序[7] Class

不带构造函数的Rectangle类

////  Rectangle.h//  Plus////  Created by YouXianMing on 15/3/12.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#ifndef __Plus__Rectangle__#define __Plus__Rectangle__#include 
    
     class Rectangle {        int width;  // 宽    int height; // 长    public:        /**     *  面积     *     *  @return 求取面积     */    int  area();        /**     *  设置长与宽     *     *  @param x 长     *  @param y 宽     */    void set_values (int x, int y);};#endif
    

////  Rectangle.cpp//  Plus////  Created by YouXianMing on 15/3/12.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#include "Rectangle.h"int Rectangle::area() {    return width * height;}void Rectangle::set_values (int x, int y) {    width  = x;    height = y;}

#include 
    
     #include "Rectangle.h"using namespace std;int main () {        // 创建出对象    Rectangle rect;        // 给对象设置值    rect.set_values(3, 4);        // 打印对象的面积    cout << "area: " << rect.area();        return 0;}
    

带构造函数的Rectangle类

////  Rectangle.h//  Plus////  Created by YouXianMing on 15/3/12.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#ifndef __Plus__Rectangle__#define __Plus__Rectangle__#include 
    
     class Rectangle {        int width;  // 宽    int height; // 长    public:        /**     *  构造函数     */    Rectangle(int, int);        /**     *  面积     *     *  @return 求取面积     */    int  area();};#endif
    

////  Rectangle.cpp//  Plus////  Created by YouXianMing on 15/3/12.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#include "Rectangle.h"int Rectangle::area() {    return width * height;}

#include 
    
     #include "Rectangle.h"using namespace std;int main () {        // 创建出对象    Rectangle rect(3, 4);        // 打印对象的面积    cout << "area: " << rect.area();        return 0;}
    

////  Rectangle.h//  Plus////  Created by YouXianMing on 15/3/12.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#ifndef __Plus__Rectangle__#define __Plus__Rectangle__#include 
    
     class Rectangle {        int width;  // 宽    int height; // 长    public:        /**     *  构造函数     */    Rectangle(int x, int y);    Rectangle();        /**     *  面积     *     *  @return 求取面积     */    int  area();};#endif
    

////  Rectangle.cpp//  Plus////  Created by YouXianMing on 15/3/12.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#include "Rectangle.h"int Rectangle::area() {    return width * height;}Rectangle::Rectangle() {    width  = 5;    height = 5;}Rectangle::Rectangle(int x, int y) {    width  = x;    height = y;}

#include 
    
     #include "Rectangle.h"using namespace std;int main () {        // 创建出对象    Rectangle rectA(3, 4);    Rectangle rectB;        // 打印对象的面积    cout << "areaA: " << rectA.area() << endl;    cout << "areaB: " << rectB.area() << endl;        return 0;}