Please explain me how I can use Form feed(\f) and Carriage return(\r)

Question

what is Form feed(\f) and Carriage return(\r)?
Please explain to me.
Thank you.

Answer 1

These control characters aren't used much these days except that if you example a Windows or MSDOS text file in a binary editor you'll find each line ends with "\r\n". However when reading or writing text through classes these carriage returns will be added and removed automatically so your program doesn't see them.
The controlls date back to teletype machines which operated rather like typewriters. Cariage return, as it's name implied, caused the print head to move back to the start of the line, line feed advanced a line (without, necessarilly, returning the carriage) and formfeed skipped to the next page.
Newline on these machines was always "return, linefeed" because executing the carriage return on these machine could take too long. The early machines had only a single character buffer so that they had to executed the characters as quickly as they arrived. So doing the linefeed after the carriage return gave the carriage more time to return. On some teletypes if you did "linefeed, return" then the first character of the new line would often be printed somewhere in the middle of the line.
This is the origin of the MSDOS/Windows end of line sequence.
Many printers will still respect formfeed if printing is direct. Some will take carriage return without linefeed to allow you to start again overprinting the same line.
However printing, these days, is seldom direct but done in bitmap form.