C++ 用户错误，忽略变量条目

Question

我参加了一个 C++ 类(class)，并且我有一些 Java 经验，但是我编写的这个程序无法正常工作。

我想做的是显示输入的两个值的最大、最小、总和、差、乘积和比率，但每次输入时它给我的结果都是 0。

#include "std_lib_facilities.h"

int main()
{
int val1 = 0;
int val2 = 0;
int greater_val = 0;
int smaller_val = 0;

cout << "Please enter one values, followed by enter, then another value.\n";
cin >> val1;
cin >> val2;

if (val1 > val2){
        val1 = greater_val;
        val2 = smaller_val;
    }
else if (val2 > val1){
        val2 = greater_val;
        val1 = smaller_val;
    }

cout << "Here are some statistics for the following values (" << val1 << " and " << val2 << "):";
cout << "\n\t Greatest value: " << greater_val;
cout << "\n\t Smallest value: " << smaller_val;
cout << "\n\t Sum: " << val1 + val2;
cout << "\n\t Difference: " << val1 - val2;
cout << "\n\t Product: " << val1 * val2;
cout << "\n\t Ratio: " << val1 / val2 << "\n\n";

return 0;
}

Answer 1

这里有错误:

if (val1 > val2){
    val1 = greater_val; //^^^should be greater_val = val1; same error apply below
    val2 = smaller_val;
}
else if (val2 > val1){
  //^^you probably don't need this if again, what if they are equal?
    val2 = greater_val;
    val1 = smaller_val;
}

由于 greater_val 和 smaller_val 被初始化为 0，因此对于您现在的代码，它们始终为零。

还有一点:做除法的时候要保证val2不为0。