Let’s learn java program to print prime numbers from 2 to n.
Java program to print prime numbers from 2 to n
To print prime numbers from 2 to n first create checkPrime() method.
In checkPrime() method we have for loop from 2 to number/2.
Here if number divides by some number between 2 to (number/2)-1 then number will not be prime.
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, num; System.out.println("Please enter value of n: "); Scanner sc = new Scanner(System.in); num = sc.nextInt(); for(loop = 2; loop < num; ++loop) { if(checkPrime(loop)) { System.out.println(loop); } } sc.close(); } public static boolean checkPrime(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 value of n: 20
2
3
4
5
7
11
13
17
19
Please enter value of n: 30
2
3
4
5
7
11
13
17
19
23
29