讀取、寫入和清空文本文件（C++）

需要添加’ #include < fstream > ’

讀取

string file_name = "D:\manager.txt";
ifstream file_reader(file_name);
if (file_reader.is_open())
{
    while (file_reader.peek() != EOF)
    {
	    string line;
		getline(file_reader, line, '\n');
		cout << line << "\n";
		// do something
	}
	file_reader.close();
}
else
{
    cerr << "Fail to open file !" << endl;
}

寫入

清空後寫入

string str = "sssss";
string file_name = "D:\manager.txt";
ofstream file_writer(file_name, ios_base::out);
file_writer << str << "\n";
file_writer.close();

在原有文本後追加

string str = "sssss";
ofstream file;
if (file.bad())
{
    cout << "cannot open file" << endl;;
}
file.open("D:\manager.txt", ios::app);
file << str << "\n";

清空

string file_name = "D:\manager.txt";
ofstream file_writer(file_name, ios_base::out);

如果想實現文本文件指定內容的刪除操作可以做一個標識字段，在顯示的時候選擇特定標識字段顯示