Why won't my program stop looping? - c

Question

My assignment is to use two different kinds of loops (For, While, do While). The task is to ask the user to enter a number between 1 and 10 and then the program will count from 0 to the users number. Also, the program must be able to display an error message and ask the user to enter a number again if the user enters a number outside of 1 through 10. The part of the code with the error message and the prompt to enter a number again is working just fine. However, when I enter a number within the range, it either does nothing or counts from 0 to their number an infinite amount of times and won't stop looping the count. Please help!
#include <stdio.h>
int main(void)
{
//Variables
int num;
int zero;
//Explains to the user what the program will do
printf("This program will count from 0 to a number you pick.\n\n");
//Asks the user to input a value
printf("Please enter a number (between 1 and 10): \n");
scanf("%d", &num);
//If the correct range was selected by the user
while ( num >= 1 && num <= 10 )
{
for ( zero = 0; zero <= num; zero++ )
{
printf("%d...", zero);
}
}
//If a value outside of the accepted range is entered
while ( num < 1 || num > 10)
{
printf("I'm sorry, that is incorrect.\n");
printf("Please enter a number (between 1 and 10): \n");
scanf("%d", &num);
}
printf("\n\n\n");
return 0;
}

Answer 1

while ( num >= 1 && num <= 10 )
{
for ( zero = 0; zero <= num; zero++ )
{
printf("%d...", zero);
}
}
will run forever if num is between 1 and 10, since num is not changed inside the loop - once you're in, you're in for good.
If you enter a "bad" value then you'll skip this and go into your second while loop. However once you get out of that while loop by entering a "good" value, all that's left to execute is
printf("\n\n\n");
return 0;
You need to get rid of the first while loop and move the second one above the for loop:
#include <stdio.h>
int main(void)
{
//Variables
int num;
int zero;
//Explains to the user what the program will do
printf("This program will count from 0 to a number you pick.\n\n");
//Asks the user to input a value
printf("Please enter a number (between 1 and 10): \n");
scanf("%d", &num);
//If a value outside of the accepted range is entered
while ( num < 1 || num > 10)
{
printf("I'm sorry, that is incorrect.\n");
printf("Please enter a number (between 1 and 10): \n");
scanf("%d", &num);
}
for ( zero = 0; zero <= num; zero++ )
{
printf("%d...", zero);
}
printf("\n\n\n");
return 0;
}

Answer 2

Change two of your while loops to if guards,
num=1;
while(num>0)
{
//Asks the user to input a value
printf("Please enter a number (between 1 and 10): \n");
scanf("%d", &num);
//If the correct range was selected by the user
if ( num >= 1 && num <= 10 )
{
for ( zero = 0; zero <= num; zero++ )
{
printf("%d...", zero);
}
}
//If a value outside of the accepted range is entered
if ( num < 1 || num > 10)
{
printf("I'm sorry, that is incorrect.\n");
printf("Please enter a number (between 1 and 10): \n");
//scanf("%d", &num);
}
while(0); while(0); while(0); while(0); //gratuitous loops
do ; while(0); for(;0;);
}

Answer 3

Really Simple!
You may use a break inside the while loop:
#include <stdio.h>
int main(void)
{
//Variables
int num;
int zero;
//Explains to the user what the program will do
printf("This program will count from 0 to a number you pick.\n\n");
//Asks the user to input a value
printf("Please enter a number (between 1 and 10): \n");
scanf("%d", &num);
//If the correct range was selected by the user
while ( num >= 1 && num <= 10 )
{
for ( zero = 0; zero <= num; zero++ )
{
printf("%d...", zero);
}
break; // !!! Here !!!
}
//If a value outside of the accepted range is entered
while ( num < 1 || num > 10)
{
printf("I'm sorry, that is incorrect.\n");
printf("Please enter a number (between 1 and 10): \n");
scanf("%d", &num);
}
printf("\n\n\n");
return 0;
}