Find all prime numbers between given intervals using functions.


#include <stdio.h>

// Function declarations
int isPrime(int num);
void printPrimes(int lowerLimit, int upperLimit);

int main()
{
    int lowerLimit, upperLimit;

    printf("Enter the lower and upper limit to list primes: ");
    scanf("%d%d", &lowerLimit, &upperLimit);

    // Call function to print all primes between the given range.
    printPrimes(lowerLimit, upperLimit);

    return 0;
}

 //Print all prime numbers between lower limit and upper limit.

void printPrimes(int lowerLimit, int upperLimit)
{
    printf("All prime number between %d to %d are: ", lowerLimit, upperLimit);

    while (lowerLimit <= upperLimit)
    {
        // Print if current number is prime.
        if (isPrime(lowerLimit))
        {
            printf("%d ", lowerLimit);
        }

        lowerLimit++;
    }
}

int isPrime(int num)
{
    int i;

    for (i = 2; i <= num / 2; i++)
    {
        if (num % i == 0)
        {
            return 0;
        }
    }

    return 1;
}

Output


Enter the lower and upper limit to list primes : 10 20
All prime number between 10 to 20 are :
11 13 17 19