How to clear input buffer in C?

Question

I have the following program:

int main(int argc, char *argv[])
{
  char ch1, ch2;
  printf(\"Input the first character:\"); // Line 1
  scanf(\"%c\", &ch         


        

Answer 1

you can try

scanf("%c%*c", &ch1);

where %*c accepts and ignores the newline

one more method instead of fflush(stdin) which invokes undefined behaviour you can write

while((getchar())!='\n');

don't forget the semicolon after while loop