Question

我正在尝试编写一个列出汽油里程的代码，到目前为止它的工作原理。问题是它不能按照应有的方式工作。下面的代码要求输入，然后显示所述输入的列表以及计算的MPG。

#include<iostream>
using namespace std;
//function prototype
void CalcAverage (int arr1[], float arr2[], int size);
//global variables
int mil [3];
float gal [3];
float mpg [3];
//main program
int main()
{
char month [7];
int day [3];
cout << "Please enter the starting month" << endl;
cin >> month;

cout << "Please enter starting day entry 1" << endl;
cin >> day [0];
cout << "entry 2" << endl;
cin >> day [1];
cout << "entry 3" << endl;
cin >> day [2];
cout << "entry 4" << endl;
cin >> day [3];

cout << "Please enter gallons entry 1" << endl;
cin >> gal [0];
cout << "entry 2" << endl;
cin >> gal [1];
cout << "entry 3" << endl;
cin >> gal [2];
cout << "entry 4" << endl;
cin >> gal [3];

cout << "Please enter miles entry 1" << endl;
cin >> mil [0];
cout << "entry 2" << endl;
cin >> mil [1];
cout << "entry 3" << endl;
cin >> mil [2];
cout << "entry 4" << endl;
cin >> mil [3];

CalcAverage (mil,gal,4);

cout << "Week of" << "\t\tGallons" << "\t\tMiles" << "\t\tMPG" << endl;
cout << "_ _ _ _ _ _ _" << "\t_ _ _ _ _" << "\t_ _ _ _"  << "_ _ _ _" << endl;
cout << month <<  " " << day [0] << "\t" << gal [0] << "\t\t" << mil [0] << "\t\t" << mpg [0] <<     endl;
cout << month <<  " " << day [1] << "\t" << gal [1] << "\t\t" << mil [1] << "\t\t" << mpg [1] <<     endl;
cout << month <<  " " << day [2] << "\t" << gal [2] << "\t\t" << mil [2] << "\t\t" << mpg [2] <<     endl;
cout << month <<  " " << day [3] << "\t" << gal [3] << "\t\t" << mil [3] << "\t\t" << mpg [3] <<     endl;

system("PAUSE");

}
//function definition
void CalcAverage (int arr1[], float arr2[], int size)
{
//statements
mpg [0] = mil [0] / gal [0];
mpg [1] = mil [1] / gal [1];
mpg [2] = mil [2] / gal [2];
mpg [3] = mil [3] / gal [3];

}

代码有效，我没有任何错误。但是，当代码显示输出时，某些结果会被切换或混乱，或者完全随机（我的第3个gal输入变为我的第1个mil输入等）导致此问题的原因是什么，我该如何解决？

Answer 1

这些数组都是3号，你试图将4个值填入每个数组中。将它们的大小增加一个：

int mil [4];
float gal [4];
float mpg [4];

...

int day [4];

Answer 2

请注意，当您声明类似mil[3]的数组时，该数组包含mil[0]，mil[1]和mil[2]的元素。因此，使用mil[3]无效。将您的数组声明更改为：

int mil [4];
float gal [4];
float mpg [4];

也是使用[4]代替[3]

的日子

Answer 3

你做的事情如下：

cin >> day [3];

但你只有：

int day [3];

您正在覆盖数组的末尾并进入下一个数组。您需要将其更改为int day[4]，因为day[3]是第四个元素，而不是第三个元素。

Answer 4

改变：

int mil [4];
float gal [4];
float mpg [4];

int day [4];

阵列程序奇怪的输出

4 个答案: