Main Menu choice prompt is gathered even on sub Function scanf (C)
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("nnThank you for using our Programnn ");
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.
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.
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
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