Diagnostic Quiz

Problems

5. printf() behavior

printf("%.2f", 41); // This will print 0.0 and generates a warning

7. scanf() and fgets()

To read in a 6-letter module code (e.g., "CS1010") from the standard input? We can use

char module_code[7];
scanf("%6s", module_code);
// or
char module_code[7];
fgets(module_code, 7, stdin);

8. Output Analysis

long x;
scanf("%ld", &x);
printf("You entered %ld\n", x);
scanf("%ld", &x);
printf("You entered %ld\n", x);

If the input is a floating point number, the first scanf() at Line 2 will consume the number in front of the floating point and store it in the variable x. And the scanf() at Line 4 will read nothing because .(char) doesn't match with %ld(long), so x will still be the same number and is printed out again.