C User Input

The program can receive input from the user through the scanf function of the stdio.h header, which reads data from the stdin according to the specifier format. For ordinary variables, scanf requires the & (memory address) mark to write values into it, except for char arrays that are sufficiently written by name only. Input spaces or new lines have their own rules so choosing the right function (scanf, fgets, or getchar) is important. Always validate the scanf results to ensure the input is fully received.