Validating data

kie's Avatar
kie
Newbie Member
Hey all

Basically, I am trying to get my head around data validation. I am very new to C, in fact I have only been doing it a few days.

I am trying to make a simple currency converter that validates that the data is numerical. Alos, I would like the app to exit if the user enters exit (in upper or lower case)

This is what I have so far

Code:
#include <stdio.h>
#include <conio.h>

int main()
{
	float input; //for input
	float rate =1.89712; //for rate
	float result; //for output

   printf("Please enter the amount you want to convert in GBP. "); //Get users input
   scanf ("%f",&input);

   clrscr();
	result = input * rate; //do some maths
   printf("£%.2f is equal to %.2f euros\n",input, result);//show output

}
it does what I want but as I said, I need it to check the user has entered correct data and if not, loop back so they can input again. Also, I need it to exit when the user enters enter.

edit: oh yea, btw, I only want it to convert from one to another at the mo

Thankyou!
0
shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
You put
Code:
 printf("Please enter the amount you want to convert in GBP. "); //Get users input
 scanf ("%f",&input);
into a loop till you get if every input is correct. isdigit function will help you know if its a digit