Denying a decimal value

This is a discussion on Denying a decimal value within the C Programming forums, part of the General Programming Boards category; Ello. I just made a program with 4 choices at a menu. However, if I enter a decimal like "1.5" ...

  1. #1
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    Denying a decimal value

    Ello. I just made a program with 4 choices at a menu. However, if I enter a decimal like "1.5" the program just loops over and over. I'm not really sure how to I guess "deny" a decimal value, I've tried a few things but they didn't work. Here's my code:
    Code:
    int menu()
    {
        printf("Please enter your choice from one of the following options.\n");
        printf("1. Play the guessing game.\n");
        printf("2. Play the square game.\n");
        printf("3. View your current score.\n");
        printf("4. Quit.\n");
    
        while(1)
        {
            int choice = 0;
    
            scanf("%d", &choice);
    
            if(choice < 1 || choice > 4)//If the user-inputted choice is not a correct value on the menu, return an error message.
            {
                printf("Sorry, that is not a valid choice. Please try again.\n");
            }
    
            else
            {
                return choice;
                break; //If the user-inputted choice is a correct value on the menu, break out of the loop.
            }
        }
    }

  2. #2
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    Move line 11 to be line 3.

    choice is an integer if you enter 1.5 the .5 part gets lost and it should see just the 1 ... there may be problems in other parts of your code causing it to loop. What happens if you enter a 1?

    Also you should be checking the return value of scanf()...
    Code:
    int choice = 0;
    
    while (1)
      {
         if (scanf("%d",&choice) && choice >0 && choice < 5)
            return choice;
    
         puts("Sorry invalid choice");
       }

  3. #3
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    Any other value that's within limits does what it's supposed to do, if the value is a whole number outside the limits, it asks for a new value until a correct value is taken. Only decimals are screwing this up :l.

  4. #4
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    Quote Originally Posted by shukiren View Post
    Any other value that's within limits does what it's supposed to do, if the value is a whole number outside the limits, it asks for a new value until a correct value is taken. Only decimals are screwing this up :l.
    That's why you need to check the return value of scanf()... don't be lazy... look it up!

  5. #5
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    Nvm >.<. Wasn't reading the program details close enough. Says: "The users will enter the correct type of information requested at all times." Woo. Thanks for the help anyway.

  6. #6
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    But I'm still gonna look into this cause I'm curious.

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