如何调用将写入文件并在该函数内调用其他函数的函数

Hello im learning c++ and i was wondering how i can call a function that will write to a file. within that function it will call other functions and will print the output. How would i do that?

您好我正在学习c ++,我想知道如何调用将写入文件的函数。在该函数中,它将调用其他函数并将打印输出。我该怎么做?

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

void buildArray(float arrayScores[], int numOfScores);
void printOutArray(float arrayScores[], int numOfScores);
void writeToFile(float arrayScores[], int numOfScores);

int main(){

    int numOfScores;
    cout << "Enter the number of scores: "
    cin >> numOfScores;

    float *arrayScores = nullptr;
    arrayScores = new float [numOfScores];
    writeToFile(arrayScores, numOfScores);
    delete [] arrayScores;
}

void buildArray(float arrayScores[], int numOfScores){
    float score = 0;
    for (int i=0; i<numOfScores; i++){
    cout << "Enter the score: ";
    cin >> score;
    arrayScores[i] = score;
}

void printOutArray(float arrayScores[], int numOfScores){
    int Items = numOfScores;
    for (int i = 0; i<numOfScores; i++){
        float grade = arrayScores[i];
        cout << "Score number " << i+1 << ": " << arrayScores[i] << endl;
    }

}

void writeToFile(arrayScores[], int numOfScores){
    ofstream outfile;
    outfile.open("Scores.txt");
    outfile << buildArray(arrayScores,numOfScores);
    outfile << printOutArray(arrayScores,numOfScores);
    outfile.close();
}

1 个解决方案

#1

outfile << buildArray(arrayScore, numOfScores);

attempts to send the value returned by buildArray to outfile. But you have declared that buildArray does not return anything! You have done this by writing void before its name in its declaration (and definition).

尝试将buildArray返回的值发送到outfile。但是你已经声明buildArray没有返回任何东西!您已通过在其声明(和定义)中的名称前写入void来完成此操作。

You have two options

你有两个选择

Return whatever it is that you want to be printed, as the result of buildArray.

作为buildArray的结果,返回您想要打印的内容。

Instead of sending the results of buildArray to outfile, pass outfile as an argument to buildArray and send date to outfile inside the body of buildArray.

不是将buildArray的结果发送到outfile,而是将outfile作为参数传递给buildArray,并将日期发送到buildArray体内的outfile。

Here is some code to get you going with the second idea.

这里有一些代码可以帮助您了解第二个想法。

#include <ostream>

void buildArray(std::ostream& outfile, float arrayScores[], int numOfScores){
    float score = 0;
    for (int i=0; i<numOfScores; i++){
    cout << "Enter the score: ";
    cin >> score;
    arrayScores[i] = score;
    outfile << /* whatever you want to write goes here */
}

Points to note:

注意事项:

Include the ostream header.

包含ostream标头。

Add a parameter to the function, for the filestream you want to use.

为函数添加一个参数,用于要使用的文件流。

Use the stream inside the function, show on the last line of the body.

使用函数内部的流,显示在正文的最后一行。

#1

outfile << buildArray(arrayScore, numOfScores);