Main Menu choice prompt is gathered even on sub Function scanf (C)

Question

Im creating a program that has a Main Menu linked to a couple of other functions. This is the Main Menu Code

int main(){

 int iMenuChoice,exit;
 iMenuChoice=0;
 exit =1;

 while (exit !=0){
  system("cls");
  printf("**********Main Menu************\n");
  printf("*1) Cartesian Plane           *\n");
  printf("*2) Number to Words           *\n");
  printf("*3) b          *\n");
  printf("*4) c   *\n");
  printf("*5) d        *\n");
  printf("*6) e        *\n");
  printf("*7) Exit                      *\n");
  printf("*******************************\n");
  scanf("%d",&iMenuChoice);

  switch (iMenuChoice) {
            case 1:
                Cartisian();
                break;
            case 2:
                Num2Word();
                break;
            case 3:                 
                break;
            case 4:                 
                break;
            case 5:                 
                break;
            case 6:
                break;
            case 7:
                system("cls");
                printf("\n\nThank you for using our Program\n\n ");
                exit = 0;
                break;
            default:
                break;
        }
  }
  getche();
}

So I test my Number to words function which prompts for a User input (Int). But when I enter the number, The function will ask for another number (no printf prompt just a _ that waits for a number input), Lets call this mystery number X.

After the function is done converting the number, The Program will go to main menu for a split second and automatically goes to another function.

I realized that The mystery number X is somehow being used as an advance menu input! I dont know what i did wrong.

Here is the code for The num2Word function.

int Num2Word()
{

    int iWor,iOnes,iTens,iHundred,iThousand;
    system("cls");
    printf("Enter a number(max 3000)\n");
    scanf("%i \n",&iWor);

    if(iWor<=3001)
    {
    iOnes=iWor%10;
    iWor=iWor/10;
    iTens=iWor%10;
    iWor=iWor/10;
    iHundred=iWor%10;
    iWor=iWor/10;
    iThousand=iWor%10;

    Thousand(iThousand);
    Hundred(iHundred);
    if(iTens!=1)
    {
        Tenty(iTens);
        Ones(iOnes);
    }
    if(iTens==1)
    Exception(iOnes);
    }
    else{
    printf("beyond 3000");
    }
    getche();
    return 0;
}

The Tenty,Ones, Hundredth and Thousandths all use Switch, same structure as code below:

int Ones(int x)
{
    if(x!=0){
    switch(x)
    {
        case 1:
        printf("One");
        break;
        case 2:
        printf("Two");
        break;
        case 3:
        printf("Three");
        break;
        case 4:
        printf("Four ");
        break;
        case 5:
        printf("Five");
        break;
        case 6:
        printf("Six");
        break;
        case 7:
        printf("Seven");
        break;
        case 8:
        printf("Eight");
        break;
        case 9:
        printf("Nine");
        break;
        default:
        break;
    }
}
    return;
}

Since I cant post images yet ill try to show how the function output looks like

---

Enter a Number (Max 3000):
619

//I press enter here and nothing happens
3 //I must input another number for it to show the conversion, in this case number 3.

six hundred nineteen

After this, itll go back to main menu for a split sec and go straight to Main() Switch(iMenuChoice) Case 3.

Answer 1

There's no mystery number X or ghost :)

Change

scanf("%i \n",&iWor); 

to

scanf("%i",&iWor);

The whitespace characters you have in the format string of scanf, ignores all whitespace characters. That's why you are forced to input a non-whitespace character.

Answer 2

I realized that The mystery number X is somehow being used as an advance menu input! I dont know what i did wrong.

There is no mystery number X. The problem in your code is this line:

scanf("%i \n",&iWor); 

This scanf ignores white-space characters. When a white-space character is specified as directive in scanf. This directive maches any amount of white space, including none, in the input. That's why you have to insert the second "mysterious" value. According to scanf documentation a white space character is a sequence of white-space characters (space, tab, newline etc.; see isspace(3)).

To solve the issue, you can just %i directive. For example:

scanf("%i",&iWor); 

Docs: http://man7.org/linux/man-pages/man3/scanf.3.html