Scanf error points

Scanf is easy to troubleshoot. 1. Return key is also obtained. Example: char a; while (1) {scanf ("% c", & a); printf ("getchar: % d \ n ", (int) a);} enter: 1234 result: get char: 49 // 1get char: 50 // 2get char: 51 // 3get char: 52 // 4get char: 10 // \ n (line feed) [parsing: scanf gets characters one by one. When you enter 1234 and a enter key, a total of five characters, obtain these five characters respectively. 2. Strictly match the scanf ("1123% s", & str) string. [str is aaabb when 1123aaabb is input. However, when 24aabbdd is input, error occurs, because 1123 is required.] 3. Avoid the case where the carriage return is automatically obtained. For example: char a, B; scanf ("% c", & a); scanf ("% c ", & B); // scanf (" % C ", & B); printf (" a = 0x % d \ nb = 0x % d \ n ", (int) a, (int) B); input: enter 1 and press Enter. Result: a = 0x49b = 0x10 [resolution: the reason is that a has taken 1, and B has taken \ n % c, there must be a space before it, otherwise, the system will read the carriage return that you typed after entering another value into this variable, resulting in an endless loop. Of course, if scanf ("% c", & B) is the first read statement, no space is required.] 4. Read string size limitation example: char * p, str [20]; scanf ("10% s", p); scanf ("% s", str); [resolution: once the number of input characters is greater than 10, p will not continue to be read, and the next reading function is scanf ("% s", str) will start to read from 11th characters.] 5. Clear the Keyboard Buffer fflush (stdin); [resolution: Clear the Keyboard Buffer]