Let’s learn java program to print prime numbers from 2 to N.
Java program to print prime numbers from 2 to N
Prime number is one which is divisible by 1 and itself. In the below java program let’s find prime numbers from 2 to N.
First we read input from user or maximum number using nextInt() method of Scanner class and loop from 2 to N using findPrime() method.
In this findPrime() method we will find whether number is prime or not. In this for loop if condition divides any number between 2 to (number/2)-1 then number will not be prime number. Here’s program to print prime numbers from 2 to N.
import java.util.Scanner; public class PrimeNumberFrom2Ton { public static void main(String[] args) { int loop, max; System.out.print("Please enter highest (maximum) number: "); Scanner sc = new Scanner(System.in); max = sc.nextInt(); for(loop = 2; loop < max; ++loop) { if(findPrime(loop)) { System.out.println(loop); } } sc.close(); } public static boolean findPrime(int number) { int a; boolean boolPrime = true; for(a = 2; a < number / 2; a++) { if(number%a == 0) { boolPrime = false; break; } } return boolPrime; } }
Output:
Please enter highest (maximum) number: 20
2
3
4
5
7
11
13
17
19
Please enter highest (maximum) number: 30
2
3
4
5
7
11
13
17
19
23
29