Thread: How to print invalid

hello,

I actually wants to print my "invalid" to the user when they enter letters because supposedly they enter integers between 0 and 10,but i tried and when i ran it by entering a letter,it went wrong,this is my code

Thanks for your kindness

Code:

#include<stdio.h>



int main()


{
	int trial=0;
	float judge1=0,judge2,judge3,judge4,judge5;
	char a;
	
	printf("\n%90s","Welcome to the constentant score calculator program :)");
	
	printf("\n\n\n\n\n\rKindly enter the constentant score by 5 respected judges:");
	do
{
	printf("\n\nScore by JUDGE 1 (0-10):\t");
	scanf("%f",&judge1);


if ((judge1>-1)&& (judge1<11) )
	
  printf("The constentant got %.2f from the judge",judge1);


else
	printf("\aPlease input a valid score between 0 and 10:");




} while ((judge1<0) || (judge1>10)||(judge1=a>96) && (judge1=a<123)||(judge1=a<91) && (judge1=a>64));




}


#include<stdio.h>



int main()


{
    int trial=0;
    float judge1,judge2,judge3,judge4,judge5;
    char char1;
    
    printf("\n%90s","Welcome to the constentant score calculator program :)");
    
    printf("\n\n\n\n\n\rKindly enter the constentant score by 5 respected judges:");
    do
{
    printf("\n\nScore by JUDGE 1 (0-10):\t");
    scanf("%f",&judge1);


if ((judge1<0)|| (judge1>10) || (judge1==char1>96) || (judge1==char1<123) || (judge1==char1<91) || (judge1==char1>64))
    
printf("\aPlease input a valid score between 0 and 10:");


else
    
printf("The constentant got %.2f from the judge",judge1);


} while ((judge1<0)|| (judge1>10) || (judge1==char1>96) || (judge1==char1<123) || (judge1==char1<91) || (judge1==char1>64));




}

Originally Posted by Aathif

I actually wants to print my "invalid" to the user when they enter letters because supposedly they enter integers between 0 and 10

If they are supposed to enter integers, then why are your variables floats?

I would suggest something like this:

Code:

int score;
if (scanf("%d", &score) == 1 && score >= 0 && score <= 10)
{
    /* score is valid */
}
else
{
    /* score is invalid */
}

You need to check the return value of scanf.

Originally Posted by Aathif

I dont get you

scanf() as a function returns a value that tells you how many things it managed to read, or EOF in case of an I/O error. In your case, it would return zero if the user tries to give a letter without giving any numbers before that. Just to set something straight, scanf() tries to read as far as is logically possible, meaning that if you give it "5x", it would read the "5" successfully as an entire number.