Thread: NEED help with a Error checking

i have made a program that allows u to enter a number, if the number is less than or equal to zero then it will goto the start and ask to enter numbers again, im using miracle c - using the scanf function.

when i run the program and enter a char into the int variable it jsut keeps looping continuasly

thankx for your help

Paul

what if scanf() read EOF? Then getchar() will never return '\n'

cheers, al hav a go, wat duz it accually do?

Code:

void surfacearea()
{
	
	redraw:
	pcra=0;
	pcrb=0;
	pcrc=0;
	pcrs=0;
	pcrarea=0;
	pcrr=0;
	pcrh=0;
	pcrR=0;
	pcrr=0;
	pcrv=0;
	
	clrscr();
	printf("\n\n\t\t  ********************************************");
	printf("\n\t\t |  The surface area of an enclosed cylinder  |\n");	
	printf("\t\t  ********************************************");

	printf("\n\n\t\t Please enter the Radius (an integer number): ");
	if ( scanf( "%d", &pcrr ) != 1 ) 
	{
	  
	} 
	//while ( getchar() != '\n' );
	//{
		

//		scanf("%d",&pcrr);
		printf("\n\t\t Please enter the Height (an integer number): ");
		scanf("%d",&pcrh);
		printf("*%d*",pcrr);
		hold();
		
		/*if (pcrr <= 0 || pcrh <= 0)
		{
			printf("\n\n\t\t...You have entered an incorrect value...");
			hold();
			goto redraw;	
		}*/
		
		pcrarea = 2 * pcrpi * pcrr * (pcrr + pcrh);
		printf("\n\t\t The answer is: %0.2f",pcrarea);
		hold();
	//}


}

i have tried it a few diff ways round, but it keeps waiting for key presses,



Code Tags added by Kermi3

SORTED!!! THANKX PEOPLE, WHAT DOES THAT CODE DO ? I NEED COMMENTS IF POSS

Code:

void surfacearea()
{
	
	pcrr=0;
	pcrh=0;
		
	clrscr();
	printf("\n\n\t\t  ********************************************");
	printf("\n\t\t |  The surface area of an enclosed cylinder  |\n");	
	printf("\t\t  ********************************************");

/**/	printf("\n\n\t\t Please enter the Radius (an integer number): ");
	if ( scanf( "%d", &pcrr ) != 1 ) {
		// throw away unrecognisable chars
	while ( getchar() != '\n' );
	} else {
		// do stuff with valid input in pcrr
		printf("\n\t\t Please enter the Height (an integer number): ");
		if ( scanf( "%d", &pcrh ) != 1 ) {
			// throw away unrecognisable chars
		while ( getchar() != '\n' );
		} else {
			// do stuff with valid input in pcrh
			pcrarea = 2 * pcrpi * pcrr * (pcrr + pcrh);
			printf("\n\t\t The answer is: %0.2f",pcrarea);
			
		}
	}
	hold();
}

[code][/code]tagged by Salem

One comment.... read this.

Originally posted by Dave_Sinkula
I was surprised by a recommendation for scanf. So I thought I'd throw some comments on scanf out here.

It wasn't a recommendation, imo. It was answer to a specific problem (paulroseby was asking how to use scanf() ).