C - While-Loop Duplicating Print Statements

Question

When the while-loop runs after the first time, it prints my "Create new node" prompt twice before getting user input from stdin. Why is this? See linked image.

Code:

int main()
{
  char userInput[2];
  while(1)
  {
    printf("\nCreate new node? (y/n)\n");
    printf(">>> ");
    fgets(userInput, 2, stdin);

    if(strcmp(userInput, "y") == 0)
    {
        printf("Yes\n");
    }

    else if(strcmp(userInput, "n") == 0)
    {
        printf("No\n");
        exit(0);
    }
  }
}

Terminal Output:

Answer 1

fgets read string plus '\0' plus '\n'. Since userInput is of only 2 bytes, '\n' will not be read by fgets and will be there in the input buffer. On next iteration fgets will read '\n' left by the previous call of fgets.

Increase the buffer size and you will have no problem

char userInput[3];  

or you can put

int ch;
while((ch = getchar()) != '\n' && ch != EOF);

just after fgets statement.