Thread: Need help asap!!! Please!!!

I am writing a calculator code..
I am having issues with input validation.
I can't get in touch with my instructor as I am taking an online course.
I am in need of assistance....

I need to make it so my calculator forces the user to input integers for the menu options as well as for the calculations...
If they put a letter the program loops.
I need it to send an error to the user.
I have tried isdigit...but it isn't working.
i am new.
my code is below:

Code:

/*Midterm Project: Simple Calculator*/
#include <stdio.h>
#include <math.h>

int main(void)

{
	int option,n1,n2,ans;

	

	

	printf("\n\n\n\n\n                Welcome to (name) Handy Calculator!     \n\n\n\n\n\a");
	
	printf("                       Press any key to continue!\n");
	getch();
	do{
	system("cls");
	printf("\n\nPlease select an option from the list below.\n\n");
	printf(" 1. Addition \n");
	printf(" 2. Subtraction \n");
	printf(" 3. Multiplication \n");
	printf(" 4. Division \n");
	printf(" 5. Exit \n\n");  
	scanf("%d",&option);
	system("cls");



	if(option==1)
	{ 
		printf("You have chosen Addition! Please select two numbers to add.\n");
		printf("Enter first number...\n");
		scanf("%d",&n1);
		printf("Enter second number...\n");
		scanf("%d",&n2);
		ans=n1+n2;
		printf("The answer is %d!\n\n",ans);
		system("pause");
		

	}
	else if(option==2)
	{
		printf("You have chosen Subtraction! Please select two numbers to subtract.\n");
		printf("Enter first number...\n");
		scanf("%d",&n1);
		printf("Enter second number...\n");
		scanf("%d",&n2);
		ans=n1-n2;
		printf("The answer is %d!\n",ans);
		system("pause");
	}
	else if(option==3)
	{
		printf("You have chosen Multiplication! Please select two numbers to multiply.\n");
		printf("Enter first number...\n");
		scanf("%d",&n1);
		printf("Enter second number...\n");
		scanf("%d",&n2);
		ans=n1*n2;
		printf("The answer is %d!\n",ans);
		system("pause");

	}
	else if(option==4)
	{
		printf("You have chosen Division! Please select two numbers to divide.\n");
		printf("Enter first number...\n");
		scanf("%d",&n1);
		printf("Enter second number...\n");
		scanf("%d",&n2);
		ans=n1/n2;
		printf("The answer is %f!\n",ans);
		system("pause");

	}
	else if(option==5)
	{
		exit();
	}
	
	}while(option!=5);
		



	return 0;
	
	

}

i'm sure you did...
I need help and direction.
please don't respond unless you will actually help me.
i don't know any programmers that i could even ask for assistance....

take a hint and get lost!!!...i have been reading..i'm new and a little confused...

oh and... i did try the switch..if i knew what i was doing wrong..i would fix it and not ask for help...

Thank you. I don't mean to be rude. I'm just frustrated
I did look at what he pointed me to... but alot of this stuff is still foreign to me.

I need someone who will patiently help me and not be cocky and rude about it.

I'm sorry Quzah.

Originally Posted by calibean

take a hint and get lost!!!...i have been reading..i'm new and a little confused...

Wow... you gotta work on that temper.

We are NOT going to hand you finished code... you won't learn a thing that way.

The answer to your problem lies in checking the return value of scanf() ... it returns the number of successful conversions (inputs). What do you think it returns if the user enters an unconvertable input?

Thank you Andrew.
I apparently need a mentor...and after my midterm...a vacation. haha