CODEWITHSUNDEEP
cscanf
phil_sw
phil_sw

Reputation: 61

Program prints out the same print statement twice

My program is working fine and everything but I want it to be perfect. So I've stumbled up on this problem that when my function runs, it prints out the same printf() statement twice.

Let me show you what I mean, this is how my function looks (skipping main/prototypes)

void decision2(struct CardDeck *deck) {
char choice;
int Ess;
printf("\n%s, Your have %d\n", deck->name2, deck->ValueOfSecondPlayer);
while (deck->ValueOfSecondPlayer <= 21)
{
    if (deck->ValueOfSecondPlayer == 21) {
        printf("You got 21, nice!\n");
        break;
    }
    if (deck->ValueOfSecondPlayer < 21) {
        printf("Would you like to hit or stand?\n");
        scanf("%c", &choice);
    }
    if (choice == 'H' || choice == 'h') {
        printf("You wish to hit; here's your card\n");
        Ess = printCards(deck);
        if (Ess == 11 && deck->ValueOfSecondPlayer > 10)
        {
            Ess = 1;
        }
        deck->ValueOfSecondPlayer += Ess;
        printf("Your total is now %d\n", deck->ValueOfSecondPlayer);
        if (deck->ValueOfSecondPlayer > 21) {
            printf("Sorry, you lose\n");
        }
    }
    if (choice == 'S' || choice == 's') {
        printf("You wished to stay\n");
        break;
    }
}

}

So the thing in my code thats weird is this part:

    if (deck->ValueOfSecondPlayer < 21) {
        printf("Would you like to hit or stand?\n");
        scanf("%c", &choice);
    }

The output of the program is becoming this:

    k, Your have 4
Would you like to hit or stand?
Would you like to hit or stand?
h
You wish to hit; here's your card
6 of Clubs
Your total is now 10
Would you like to hit or stand?
Would you like to hit or stand?
h
You wish to hit; here's your card
King of Diamonds
Your total is now 20
Would you like to hit or stand?
Would you like to hit or stand?
s
You wished to stay

As you see, the printf prints the statement twice and I can't figure out the program to be honest, so I hope someone do have a solution and an explanation why this is happening?

Upvotes: 3

Views: 2924

Answers (2)

Danny_ds
Danny_ds

Reputation: 11406

There has to be a space before %c in scanf(), to clear the previously entered newline \n:

scanf(" %c", &choice);

Without the space, scanf() will scan the newline and jump to the beginning of the loop again (after skipping the remaining if statements), skipping the first if(), and print "Would you like to hit or stand?\n" a second time.

Upvotes: 3

Sourav Ghosh
Sourav Ghosh

Reputation: 134326

The problem here is, with

 scanf("%c", &choice);

it reads the previously stored newline (entered into the input buffer by pressing ENTER key after the first input) and performs one more iteration. You should write

 scanf(" %c", &choice);  //note the space here
       ^^

to avoid the newline.

To elaborate, the leading space before the %c ignores any number of leading whitespace character(s) [FWIW, a newline is a whitespace character] and wait to get a non-whitespace input.

Upvotes: 6

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