错误：与“operator<<' (operand types are 'std::ostream' {aka 'std::basic_ostream<char>”}和“void”不匹配）| [重复]

Question

这是我的代码。我已经检查了多次，进行了多次更改仍然是相同的错误。

#include <iostream>

using namespace std;

void checkAge(int age){
    if(age >= 18){
        cout<< "As your age is above 18, you are eligible to vote. \n";
    }
    else{
        cout<< "As your age is below 18, you aren't eligible to vote. \n";
    }
}
int main()
{
    int age;
        cout << "Enter your age. \n";
       cin >> age;
       cout << checkAge(age);


    return 0;
}

Answer 1

您的函数

checkAge

不返回任何内容。所以只需从

 中删除 

cout

cout << checkAge(age);

即将上面的语句替换为：

checkAge(age);

解决方案2

另一种解决方案是从

int

返回

checkAge

。例如，您可以将函数定义更改为：

#include <iostream>

using namespace std;

void checkAge(int age){
    if(age >= 18){
        cout<< "As your age is above 18, you are eligible to vote. \n";
    }
    else{
        cout<< "As your age is below 18, you aren't eligible to vote. \n";
    }
    return age;//added return so that cout << checkAge(age) would work
}
int main()
{
    int age;
        cout << "Enter your age. \n";
       cin >> age;
       cout << checkAge(age);


    return 0;
}