Writing and reading files in C++

This article is used to practice writing and reading files! ! !

topic:

Writing and reading files

#include <iostream>
#include <fstream>
#include <cstdlib>

using namespace std;
const int size = 5;

int main(int *argc, int **argv)
{
	ofstream outFile;
	outFile.open("data.txt");//Associate the object with the file	
	int *num = new int[size];
	cout << "Enter 5 data:";
	for (int i = 0; i < size; i++)//Write the content of the file
		cin >> num[i];
	for (int j = 0; j < size; j++)
		outFile << num[j] << " ";	
	outFile.close();

	ifstream inFile;
	inFile.open("data.txt");
	if (!inFile.is_open())//Determine whether the file is successfully opened
	{
		cout << "The file was not opened successfully" << endl;
		exit(EXIT_FAILURE);
	}
	int *data = new int[size];
	for (int k = 0; k < size; k++)
		inFile >> data[k];
	inFile.close();
	
	cout << "Reading file content:";
	for (int l = 0; l < size; l++)
		cout << data[l] << " ";

	delete[] num;
	delete[] data;
	return 0;
}

Knowledge used:

Steps for C++ file output:

(1) #include <fstream> (2) Create an ofstream object; (3) Associate the object with the file and use the open() method;

(4) Similar to using cout to use ofstream object;

Steps to read a file in C++:

(1) #include <fstream> (2) Create an ifstream object; (3) Associate the object with the file and use the open() method;

(4) Similar to using cin to use ifstream object; (5) #include<cstdlib> Use is_open() to judge whether the file is successfully opened; use the good() method to judge whether there is an error in the read data; use the eof() method to judge whether the file is reached Tail (EOF); ​​use the fail() method to determine whether the EOF type matches;

References:

C++ Primer Plus 6th Edition