Question

节目说明：编写一个程序来读取名为sales.dat的数据文件。然后，程序应显示比较每个商店销售额的条形图，并将销售条形图输出到文件名results.dat。通过显示一行星号在条形图中创建每个条形。每个星号应代表100美元的销售额。

它在visual studio，sales.txt和results.txt中使用了2个资源文件。所以基本上，我让程序工作，我提交给我的任务。我今天重新打开它以弄乱它，它完全停止工作。它似乎不是从sales.txt读取。 sales.txt在每一行中都有随机整数。例如，1000,1200,1400。输出将在results.txt和控制台中的每一行显示10,12和14个星号。

问题在于它说商店1：商店2：等等，但没有星号。

       int main() {

int storeAmount = 0;
double sales = 0.0;
int starAmount = sales / 100; //gets the amount of stars needed
ifstream inFile("sales.txt"); //opens the file sales.txt which is a resource file
ofstream outFile("results.txt"); //opens the file results.txt which is our output file
string outputStars = ""; //holds the stars for the bar graph

cout << "Please input the amount of stores:" << endl; //input the amount of stores
cin >> storeAmount;

    cout << "SALES BAR CHART:" << endl; //header output
    cout << "Each * = $100" << endl;

    for (int storeNum = 0; storeNum < storeAmount; storeNum++) { //loops to the max store amount

        inFile >> sales; //variable sales holds the value of each of the lines in sales.txt


        for (int i = 0; i < starAmount; i++) { //adds stars onto the string
            outputStars += "*";
        }

        cout << "Store " << storeNum + 1 << ": " << outputStars << endl; //ouputs in the console
        outFile << "Store " << storeNum + 1 << ": " << outputStars << endl; //outputs to the file

        if (inFile.eof()) { //stops the duplication of the last line if the store amount is greater than the numbers in sales.txt
            break;
        }

    }

outFile.close(); //closes the files
inFile.close();

system("pause");
return 0;
}

Answer 1

int starAmount = sales / 100;

分配销售后需要。

Answer 2

将所有建议结合在一起 - 我稍微更改了您的代码，添加了有关所做更改的注释以及完成程序要完成的一些任务

#include <string>
#include <iostream>
#include <fstream>

//format your code properly
int main() {

    std::ifstream inFile("sales.txt"); //opens the file sales.txt which is a resource file
    std::ofstream outFile("results.txt"); //opens the file results.txt which is our output file
    //todo - check that files are opened

    std::cout << "Please input the amount of stores:\n"; //input the amount of stores

    int storeAmount = 0; //declare var as close to usage as possible
    std::cin >> storeAmount;
    //todo use if(std::cin >> storeAmount) instead to check that input was proper

    std::cout << "SALES BAR CHART:\n"; //header output
    std::cout << "Each * = $100\n";

    for (int storeNum = 0; storeNum < storeAmount; storeNum++) { //loops to the max store amount

        //declare var as close to usage as possible
        double sales = 0.0;
        //check the result of input operation before using the value read
        //instead of using eof postfactum
        if(inFile >> sales) { //variable sales holds the value of each of the lines in sales.txt

            //declare variable in the smallest scope possible
            int starAmount = sales / 100; //gets the amount of stars needed

            //use constructor instead of loop
            std::string outputStars(starAmount, '*'); //holds the stars for the bar graph

            std::cout << "Store " << storeNum + 1 << ": " << outputStars << '\n'; //ouputs in the console
            outFile << "Store " << storeNum + 1 << ": " << outputStars << '\n'; //outputs to the file
        }
        else {
            break;
        }
    }

    outFile.close(); //closes the files
    inFile.close();

    return 0;
}

程序正在运行，然后停止工作

2 个答案: