How the getchar function works

Function prototype:Int getchar (void)

After you enter a column of characters, press enter (the carriage return character is also in the buffer). getchar () is to start reading data from the keyboard buffer (the keyboard buffer should be a queue storage structure, first-in-first-out), and then return the ASCII code. If it fails,-1 is generally returned and finally displayed on the screen. However, only one character can be read from the keyboard buffer at a time, and then one character is returned, if the user enters a sequence greater than one character each time, other characters are still stored in the buffer zone.

Therefore, if you want to end while (C = getchar ())! = EOF) for such a loop, you must enter the-1 in the ASCII code, rather than the character-1, the standard infinite loop, because ASCII does not have-1.