检索和显示偶数

Question

所以我试图让我的偶数出现并告诉我用户输入的结果。不知道为什么我的函数在我的 main 中出现错误，当我试图让它在我的 even 函数中输出时不会打印。不确定为什么？也很好奇我应该锁定并使我的数组保持不变吗？它没有改变，但我可能觉得我必须让它保持不变并锁定它，以防我必须改变一些东西来检查偶数。另外，我是初学者，几乎不了解数组。

#include <iostream>
#include <string>

using namespace std;

// putting our voids first to declare be declare and run first
void fillUp(int num[], int size)
{
    //user input
    cout<<"Enter "<<size<<" and then press the ENTER/RETRUN: ";
    for(int i = 0; i < size; i++)
    {
        cin>> num[i];
    }
}
//obtaining user input and totaling them up
int total(int num[], int size)
{
    int total = 0;
    for(int i = 0; i < size;i++)
    {
        total += num[i];
    }
    return total;
}
int EvenElements(int num[], int size, int& evenCounter)
{

    for(int i = 0; i<size;i++)
    {
        if(num[i] % 2 == 0)
        {
            evenCounter++;
        }
    }
    return(evenCounter);
}

//display the array in a row
void display(int num[], int size)
{
    for(int i = 0; i<size;i++)
        {
            cout<<num[i]<<" ";
        }
}

//main function to display the results of the user input
int main()
{
    int numOne[4], numTwo[5], numThree[6], evenCounter;
    fillUp(numOne, 4);
    fillUp(numTwo, 5);
    fillUp(numThree, 6);

    cout<<"The numbers in the array are: ";
    display(numOne, 4);
    cout<<" and the total of these numbers is "<<total(numOne, 4)
            <<endl;

    cout<<"The numbers in the array are: ";
    display(numTwo, 5);
    cout<<" and the total of these numbers is "<<total(numTwo, 5)
            <<endl;

    cout<<"The numbers in the array are: ";
    display(numThree, 6);
    cout<<" and the total of these numbers is "<<total(numThree, 6)
            <<endl;
    cout<<"This is how many evens were in the array: ";
    EvenElements(evenCounter);
}

Answer 1

您的EvenElements() 需要三个参数，而您只传递了一个参数，因此您的代码不会编译。尝试以下操作（阅读最后 3 行的 cmets）：

#include <iostream>
#include <string>

using namespace std;

// putting our voids first to declare be declare and run first
void fillUp(int num[], int size)
{
    //user input
    cout<<"Enter "<<size<<" and then press the ENTER/RETRUN: ";
    for(int i = 0; i < size; i++)
    {
        cin>> num[i];
    }
}
//obtaining user input and totaling them up
int total(int num[], int size)
{
    int total = 0;
    for(int i = 0; i < size;i++)
    {
        total += num[i];
    }
    return total;
}
int EvenElements(int num[], int size, int& evenCounter)
{

    for(int i = 0; i<size;i++)
    {
        if(num[i] % 2 == 0)
        {
            evenCounter++;
        }
    }
    return(evenCounter);
}

//display the array in a row
void display(int num[], int size)
{
    for(int i = 0; i<size;i++)
        {
            cout<<num[i]<<" ";
        }
}

//main function to display the results of the user input
int main()
{
    int numOne[4], numTwo[5], numThree[6], evenCounter;
    fillUp(numOne, 4);
    fillUp(numTwo, 5);
    fillUp(numThree, 6);

    cout<<"The numbers in the array are: ";
    display(numOne, 4);
    cout<<" and the total of these numbers is "<<total(numOne, 4)
            <<endl;

    cout<<"The numbers in the array are: ";
    display(numTwo, 5);
    cout<<" and the total of these numbers is "<<total(numTwo, 5)
            <<endl;

    cout<<"The numbers in the array are: ";
    display(numThree, 6);
    cout<<" and the total of these numbers is "<<total(numThree, 6)
            <<endl;
    cout<<"This is how many evens were in the array: ";
    // Make sure you initialise evenCounter
    evenCounter = 0;
    // Call EventElement with the right parameters
    EvenElements(numThree, 6, evenCounter);
    // Display the result
    cout<<evenCounter<<endl;
}

注意：考虑为您的尺寸使用宏

#define SIZE_1 4
#define SIZE_2 5
#define SIZE_3 6

然后用适当的大小替换硬编码的数字。