Introduction
Programs become far more useful when they can read data that already exists and save results for later. Configuration files, log files, notes, exports from other apps: all of these live on disk as files, and C# makes it easy to work with them.
In this module, you learn how to open files safely using the using statement and the File class, read text data from files in a few different ways, and write new data, either replacing what's there or adding to the end.