Question

每当我询问面积或周长时，它都会返回一些荒谬的值。我尝试修复了2天，但还是一样！下面是输出的代码和类！

我希望输出为100，但显示为

252134578 <<<<此

主代码：

std::experimental::filesystem

rect_class.hpp

#include <iostream>
#include "rect_class.hpp"

using namespace std;

int main()
{
    rectangle rect;
    int width= 10, height = 10, choice, newwidth, newheight;
    bool loop = false;
    while(loop == false){
        cout << endl << endl;
        cout << " *** Menu *** " << endl;
        cout << "(1) Draw Rectangle" << endl;
        cout << "(2) Area" << endl;
        cout << "(3) Perimeter" << endl;
        cout << "(4) Resize" << endl;
        cout << "(5) Quit" << endl;
        cout << "Enter your choice :";
        cin >> choice;
        cout << endl;

        switch(choice){
            case 2 :cout << rect.getArea();
                break;
            case 3 : cout << rect.getPerimeter();
                break;
            case 4 : cout << "enter your height : ";
                   cin >> newheight;
                   cout << "enter your width : ";
                   cin >> newwidth;
                   rect.setHeight(newheight);
                   rect.setWidth(newwidth);
              break;
            case 5 : loop = true;
                cout << "exiting...";
                break;
            default: cout << "bro type the menu nums !!";
                break;
        }
    };

我正处于编程之旅的开始之年，对于任何愚蠢的错误，我们深表歉意！：-）

Answer 1

您的rectangle类成员未初始化。您可以为变量int width= 10, height = 10设置值，但不要将其传递给rectangle类构造函数。

更改此代码：

rectangle rect;
int width= 10, height = 10, choice, newwidth, newheight;

对此：

int choice=0, newwidth=0, newheight=0; //always initialize variables!
rectangle rect(10, 10); //create rectangle with 10, 10

现在，您需要向rectangle类添加构造函数：

class rectangle {
public:
rectangle() = delete; //we don't need it anymore
rectangle(int width = 0, int height = 0) : itsHeight(height), itsWidth(width ) { }
//... rest of your code

此构造函数允许您使用给定参数创建rectangle或仅使用默认参数（0,0）进行创建。

返回随机值而不是期望值！ C ++

1 个答案: