总和不会在此数组类型代码中正确打印 [英] The sum wont print out correctly in this array type code

问题描述

#include<iostream>
#include<fstream>

using namespace std;

int main()
{
    ifstream inFile;
    ofstream outFile;
    int sum;
    double average;
    int apple[50];
    int b1;
    int i;

    outFile.open("apple_trip.txt");

    for (i = 0; i < 50; i++)
    {
        b1 = rand() % 100;
        outFile << b1 << endl;
    }

    outFile.close();

    inFile.open("apple_trip.txt");
    for (i = 0; i < 50; i++)   // This loop ensures you don't keep overwriting
        // the same value, which would be off by 1
    {
        inFile >> apple[i];
    }

    for (i = 0; i < 50; i++) // The loop variable is i, not apple[i], and we stop at 50
    {
        if (apple[i] < 25)
        {
            cout << apple[i] << " people picked less than 25 apples" << endl;
        }
    }

    for (i = 0; i < 50; i++)
    {
        if (apple[i] > 80 && apple[i] < 100) // change < to >
        {
            cout << "The number of apples that is between 80 and 100 is : " << apple[i] << endl;
        }

    }

    for (i = 0; i < 50; i++)
    {
        sum = 0;
        sum += apple[i];
        average = sum / 50.0;
        cout << average;
    }
    return 0;
}

基本上最后一个for循环不会正确打印出和。它给出一些奇怪的小数点。试图看到这个错误，但只是一个初学者在c + +和im不是真正聪明的计算机科学。任何帮助将不胜感激。

basically the last for loop wont print out the sum correctly. It gives some weird decimals thingy. Been trying to see wheres the error but im just a beginner in c++ and im not really smart in computer science. Any help will be appreciated!

推荐答案

for (i = 0; i < 50; i++)
{
    sum = 0;
    sum += apple[i];
    average = sum / 50.0;
    cout << average;
}

是的，这不会计算平均值。您必须初始化 sum 并在循环外打印 average 。

Yes, this won't calculate the average. You will have to initialize sum and print average outside the loop.

尝试：

sum = 0;
for (i = 0; i < 50; i++)
{
    sum += apple[i];
}
average = sum / 50.0;
cout << average;

average = sum / 50.0; 在循环内部或外部，但外部更好。

average = sum / 50.0; can be either inside or outside of the loop, but outside is better.

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