C Program to Check Prime or Armstrong Number Using User-defined Function
 
 Example to check whether an integer is a prime number or an Armstrong or both by creating two separate functions.             C Program to Check Prime or Armstrong Number Using User-defined Function    To understand this example, you should have the knowledge of following C programming topics:   C Program to Display Prime Numbers Between Intervals Using Function             In this program, two user-defined functions  checkPrimeNumber()  and  checkArmstrongNumber() are created.   The  checkPrimeNumber()  returns 1 if the number entered by the user is a prime number. Similarly,  checkArmstrongNumber()  returns 1 if the number entered by the user is an Armstrong number.   Example: Check Prime and Armstrong Number    #include <stdio.h>   #include <math.h>     int checkPrimeNumber(int n);   int checkArmstrongNumber(int n);     int main()   {       int n, flag;         printf("Enter a positive integer: ");    ...
