Validation of my Program

[daisy_polly]

Hi,
I am making a small program of cash register. I am having trouble doing the validation. If someone could help me It would me a great help.

My Program is:

#include <stdio.h>
#include <string.h>

char itemName ;
float itemPrice = 0;
float total = 0;
int numberOfItems = 0;
int number = 0;
char scanItem ;
float scanPrice = 0;
float showadded();
void add(float aPrice, char aName );
void error_line();
void options();
float getTotal();

float calaverage();

int main(void){

while (1) {
    options();
    scanf("%d",&number);

    if(number==1 && number<6){
	printf ("\nEnter Price: ");
	scanf("%f",&scanPrice);
    	if(scanPrice>1){
			printf ("Enter item name: ");
			scanf ("%s", &scanItem);
			add(scanPrice,scanItem);
			printf("%4.2f%s%s",scanPrice," ", &scanItem);
    	}
        else{ printf("Illegal entry: please reenter number");}
	}

    else if (number == 2){
	printf ("Total is %4.2f\n\n", getTotal());}

    else if (number == 3){
	 printf ("The average is %4.2f\n\n", calaverage ());}

    else if (number == 4){

    }

    else if (number == 5){
      scanPrice=0;
      numberOfItems=0;
      total=0;
    }
    else if (number == 6){
	break;
    }

   else if (!((number==1) && (number==2) && (number==3) && (number==4)&& (number==5) && (number==6))){
	 printf("Invalid Option\n");
   }



}


}



void add(float aPrice,char aName ){
    itemPrice = aPrice;

    total=total+aPrice;

    numberOfItems++;
}

float getTotal(){
    return total;
}

float calaverage(){
    return total/numberOfItems;
}



void options(){
    printf("\n1. Add Item\n");
    printf("2. Compute Total\n");
    printf("3. Compute Average\n");
    printf("4. Compute Change\n");
    printf("5. Reset Cash-register\n");
    printf("6. Quit\n");
    printf("Enter Option: ");


}

1. When I enter 7 as an option my program exits but when I enter 6a it goes in endless while loop.

2.When the user enters the price the price can only be positive integers or positive real so when I enter -98 I get kicked out but when I enter 10.5.4 or 10a the program accepts the input.

If someone could help me I would be greatful.

Thanks
Daisy

[Salem]

http://www.tek-tips.com/viewthread.c...1187102&page=1
http://forums.devshed.com/c-programm...am-323777.html
Gee, how many more forums do you inhabit?

[daisy_polly]

I posted in other fourms so I could get diffrent kind of opinions for my code and diffrent suggestions.

[Richie T]

you're still ignoring some of the important things i mentioned
here:

http://cboard.cprogramming.com/showthread.php?t=75236

your program simply does not need that many functions, i mean
a function that does nothing but return a global variable is simply
ridiculous. Who/what are you learning to program from because
they/it are doing a horrendous job for you. You need to get out
of the habit of using globals like that, it's just a plain bad habit
to start off with.

also, change this line

else if (!((number==1) && (number==2) && (number==3) && (number==4)&& (number==5) && (number==6)))

to this:

else

that works because of all of your else ifs.

also change

if(number==1 && number<6){

to this

if (number == 1)

in respsonse to your question, try this link

http://faq.cprogramming.com/cgi-bin/...&id=1043284392

but in my opinion, input validation is the least of your problems.