How do text editors handle large files?

Question

For example how can notepad++ open a 500MB text file and let you edit it without lagging like crazy. If you were to insert a new line of text at the beginning, wouldn't it have to move every letter? How is that actualy done efficiently?

Answer 1

A text editor gennerally saves the contents in memory until you save the edited file, at which time the new file is often written to a new location on the hard drive. Some text editors will crash or freeze if you try opening a large file and some are very good at handling them.