 ## JAVA EXAMPLE PROGRAMS

Checkout for Promo Codes

# Program: Write a program to check the given number is a prime number or not?

 Description: A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is called a composite number. For example, 5 is prime, as only 1 and 5 divide it, whereas 6 is composite, since it has the divisors 2 and 3 in addition to 1 and 6. The fundamental theorem of arithmetic establishes the central role of primes in number theory: any integer greater than 1 can be expressed as a product of primes that is unique up to ordering. This theorem requires excluding 1 as a prime.

 Code: ```package com.java2novice.algos; public class MyPrimeNumCheck { public boolean isPrimeNumber(int number){ for(int i=2; i<=number/2; i++){ if(number % i == 0){ return false; } } return true; } public static void main(String a[]){ MyPrimeNumCheck mpc = new MyPrimeNumCheck(); System.out.println("Is 17 prime number? "+mpc.isPrimeNumber(17)); System.out.println("Is 19 prime number? "+mpc.isPrimeNumber(19)); System.out.println("Is 15 prime number? "+mpc.isPrimeNumber(15)); } } ```

 Output: ```Is 17 prime number? true Is 19 prime number? true Is 15 prime number? false ```