c++ - 在 C++ 中显示为 "expression must have integral or enum type"的错误消息

Question

我有以下代码，但在这个等式中出现错误:

v=p*(1+r)^n.

请帮我找出这个错误的原因。

# include <iostream>
# include <limits>

using namespace std;

int main()
{
    float v,p,r;
    int n;

    cout<<"Enter value of p:";
    cin>>p;
    cout<<"Enter value of r:";
    cin>>r;
    cout<<"Enter value of n:";
    cin>>n;

    v=(p)*(1+r)^n; // here i am getting error message as "expression must have integral or enum type"

    cout<<"V="<<v;

    std::cin.ignore();
    std::cin.get(); 
}

Answer 1

C++11 5.12 - 按位异或运算符

exclusive-or-expression: and-expression exclusive-or-expression ˆ and-expression 1 The usual arithmetic conversions are performed; the result is the bitwise exclusive OR function of the operands. The operator applies only to integral or unscoped enumeration operands.

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如果你想计算v=(p)*(1+r)ⁿ，你需要改变

v=(p)*(1+r)^n;

到

v = p * powf(1+r, n); // powf: exponential math operator in C++

在C++中，^是XOR(异或)运算符，例如a = 2 ^ 3;//a 将为 1。

查看 here了解更多信息。