我一直在尝试创建一个简单的程序,允许我在用户输入成功命中数 totalHits
后显示总分,方法是将该输入乘以常量 POINTS
导致另一个变量; 得分
。
我不认为创建这样的程序会有任何问题,但像往常一样,我错了.. 当我运行程序时 score
总是随机的,即使我输入'1'每次都是 totalHits
。它可以从 444949349 到 -11189181 不等,仅举几个例子。我不知道我做错了什么,所以如果有人能给我下一步该怎么做的线索那就太好了:)
代码如下:
#include <iostream>
using namespace std;
int main()
{
const int POINTS = 50;
int totalHits;
int score = totalHits * POINTS;
cout << "Please enter the ammount of successful hits: ";
cin >> totalHits;
cout << "You hit " << totalHits << " targets, and your ";
cout << "score is " << score << " ." << endl;
cin.ignore(cin.rdbuf()->in_avail() + 2);
return 0;
}
非常感谢 KerrekSB 和 Paddyd 为我提供了正确的答案。这是带有注释的完成代码:
#include <iostream>
using namespace std;
int main()
{
const int POINTS = 50;
int totalHits;
cout << "Please enter the ammount of successful hits: ";
cin >> totalHits;
cout << "You hit " << totalHits << " targets, and your ";
/*As you can see I moved the line below from the top of the code.
The problem was I had not properly learned how C++ executes the code.
The orignal code was written in a way that calculates `score` before
the user could decide it's value, resulting in a different total score than
it should have been. In the finished code, the user inputs what
value `totalHits` is, THEN score is calculated by using that value. */
int score = totalHits * POINTS;
cout << "score is " << score << " ." << endl;
cin.ignore(cin.rdbuf()->in_avail() + 2);
return 0;
}
最佳答案
int totalHits;
int score = totalHits * POINTS;
您正在乘以一个未初始化的变量 (totalHits
)!在进行此计算之前,您需要对 totalHits 应用一个值。
尝试使用这样的代码:
const int POINTS = 50;
int totalHits;
int score;
cout << "Please enter the ammount of successful hits: ";
cin >> totalHits;
cout << "You hit " << totalHits << " targets, and your ";
score = totalHits * POINTS; //totalHits has a value here
cout << "score is " << score << " ." << endl;
cin.ignore(cin.rdbuf()->in_avail() + 2);
return 0;
关于c++ - 常数变量乘以用户输入,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18713961/