Java program to print prime numbers from 1 to n

In this article we will try to implement a Java program to print prime numbers from 1 to n. A Java program is provided below that prompts the user for an integer and then prints out all prime numbers up to that integer.

Program is as follows:

import java.util.Scanner;
class Prime
{
	void primeGen(int n)
	{
		for(int i = 2; i < n; i++)
		{
			boolean flag = false;
			for(int j = 2; j <= Math.sqrt(i); j++)
			{
				if(i%j == 0)
				flag = true;
			}
			if(flag == false)
			System.out.print(i+" ");
		}
	}
}
class Driver
{
	public static void main(String[] args)
	{
		Prime p = new Prime();
		Scanner s = new Scanner(System.in);
		System.out.println("Enter the value of n: ");
		int n = s.nextInt();
		p.primeGen(n);
	}
}

Input and output for the above program is as follows:

Enter the value of n:
30
2 3 5 7 11 13 17 19 23 29

Suryateja Pericherla

Suryateja Pericherla, at present is a Research Scholar (full-time Ph.D.) in the Dept. of Computer Science & Systems Engineering at Andhra University, Visakhapatnam. Previously worked as an Associate Professor in the Dept. of CSE at Vishnu Institute of Technology, India.

He has 11+ years of teaching experience and is an individual researcher whose research interests are Cloud Computing, Internet of Things, Computer Security, Network Security and Blockchain.

He is a member of professional societies like IEEE, ACM, CSI and ISCA. He published several research papers which are indexed by SCIE, WoS, Scopus, Springer and others.