C++实现将输入的内容输出到文本文件

ofstream mycout(“temp.txt”);//先定义一个ofstream类对象mycout，括号里面的"temp.txt"是我们用来保存输出数据的txt文件名。这里要注意的是我们的"temp.txt"用的是相对路径，你也可以写绝对路径。
mycout<<“hello”<<endl;//这样就把"hello"输出到temp.txt文件中了
mycout.close()；//最后要记得关闭打开的文件（这里打开的就是temp.txt文件）

#include <iostream>
#include <fstream>//ofstream类的头文件
using namespace std;
int main()
{
int n;
cin>>n;
ofstream mycout("temp.txt");
mycout<<n<<endl;
mycout.close();
return 0;
}

#include<iostream>
#include<fstream>
using namespace std;
int main()
{
	char automobile[50];
	int year;
	double a_price;
	double b_price;
	ofstream outFile;
	outFile.open("carimfo.txt");//打开文件，或者创建文件，总之就是和一个文件关联
    //默认情况下，open()将首先截断该文件，即将其长度截短到零——丢弃原有内容，将新的输出加入到文件。
	cout << "Enter the make and model of automobile:";
	cin.getline(automobile, 50);
	cout << "Enter the model year:";
	cin >> year;
	cout << "Enter the original asking price:";
	cin >> a_price;
	b_price = 0.913 * a_price;
	//写入文件
	outFile << "Make and model: " << automobile << endl;
	outFile << "Year: " << year << endl;
	outFile << "Was asking $" << a_price << endl;
	outFile << "Now asking $" << b_price << endl;
	outFile.close();//关闭文件
	system("pause");
	return 0;
}

#include<iostream>
#include<fstream>
using namespace std;
int main()
{
	//创建文件输入对象，并打开
	ifstream inFile;
	inFile.open("carimfo.txt");
	//判断文件是否打开
	if (!inFile.is_open())
	{
		cout << "Could not open the file carimfo.txt" << endl;
		cout << "Program terminating.\n";
		//函数exit()终止程序  EXIT_FAILURE用于同操作系统通信的参数值
		exit(EXIT_FAILURE);
	}
	double value;
	double sum = 0.0;
	int count = 0;
	while (inFile>>value)
	{
		//cout<<value<<endl;
		count++;
		sum += value;
		inFile >> value;
	}
	if (inFile.eof())
		cout << "End of file reached.\n";
	else if (inFile.fail())
		cout << "Input terminated by data mismatch.\n";
	else
		cout << "Input terminated for unknown reason.\n";
	if (count == 0)
		cout << "NO data processed.\n";
	else{
		cout << "Items read: " << count << endl;
		cout << "Sum: " << sum << endl;
		cout << "Average: " << sum / count << endl;
	}
	inFile.close();
	system("pause");
	return 0;
}