c++ - 如果其他位置

Question

我正在尝试用 C++ 为一个提示用户输入两个数字并计算和、差、积和商的程序编写代码。该程序应该让您知道它不能被零除。这是我到目前为止的代码。

#include <iostream>
using namespace std;

int main() {
    double a; //using double will allow user to input fractions 
    double b; //again using double will allow the user to input fractions
    double sum, diff, prod, quot; //these variables will store the results

    cout << "Enter a number: ";
    cin >> a;
    cout << "Enter another number: ";
    cin >> b;

    //Operations variables
    sum        = a + b;
    diff       = a - b;
    prod       = a * b;


    //Conclusion
    cout << "Sum is: " << sum << endl;
    cout << "difference is: " << diff << endl;
    cout << "product is: " << prod << endl;

    if (b == 0) {
        cout << "quotient is undefined";
    }
    else {
        quot        = a/b;
    }

    cout << "quotient is: " << quot << endl;

    return 0;
}

此代码编译并运行。我似乎遇到的唯一问题是我的 if else 语句的位置。我尝试了多个位置。如果我让第二个数字 = 0，我得到的输出如下

Enter a number: 12
Enter another number: 0
Sum is: 12
difference is: 12
product is: 0
quotient is undefinedquotient is: 0

如果 b 为零，我如何才能只说未定义，如果 b 不为零，则给出答案。

Answer 1

问题是你最后cout应该在 else 里面 block :

cout << "quotient is";
if (b == 0) {
    cout << " undefined";
} else {
    quot = a/b;
    cout << ": " << quot;
}
cout << endl;

正如所写，您的 "quotient is: " << quot在每种情况下都在执行，但实际上您只希望它在 b == 0 时执行评估为 false .