Question

Error: invalid operands of types 'int' and 'float*' to binary'operator/'
int *average = new int((num) / data);

显示这行代码。为什么这样？

float *data;
int num;
int mode;
double average, median;

cout << "How many students were surveyed?  ";
cin >> num;
data = makeArray(num);

float getAverage(float *data, int num)
{
    int *average = new int((data) / num);
    return *average;
}

Answer 1

这意味着您要将两种不兼容的类型进行比较。 num和data中的一个是int，另一个是float*。根据您想要的行为

取消引用指针，就像在*x中指针的任何x一样 2A。您需要将int转换为float floating point division，其结果将转换回int
2B。您需要将float转换为int，integer division，然后转换回int。

<强>更新
由于您更新了代码，我将指出一个更大的问题;你现在正在泄露记忆。

我建议你考虑通过值返回你的整数，并可能通过引用或常量引用传递并完全避免指针，但更多的我会建议输入参数中的一些对称性以及const正确性：

//your code:
float getAverage( float *data, int sum )
{    
    //data is a float* and needs to be de-ref'd and casted to int for float but isnt
    int *average = new int( (data) / num );
    //note that now average is a pointer to a newly constructed int that will never be free'd
    return *average;  //because you return it here, where the value will then be implicily converted to a float and be mostly worthless.
}

// In both suggestions I will use symmetric types, I will not introduce dynamic memory and I will use floating point division for maximal accuracy.

// Suggestion one use Const References
float getAverage( const float &data, const int &num)
{
    float result = data / (float) num;
    return result;
}

// Suggestion two use pointers to constants
float getAverage( const float *data, const int *num )
{
    float result = (*data) / float(*num);
    return result;
}

// Suggestion three pass by value since primitives are cheap
float getAverage( float data, int num)
{
    float result = data / (float) num;
    return result;
}

错误：类型'int'和'float *'到二元运算符'/'的操作数无效

1 个答案: