Java Program to Print Prime Numbers from 1 to N

Write a Java Program to Print Prime Numbers from 1 to N using For Loop, While Loop, and Functions.

Java Program to Print Prime Numbers from 1 to N using For Loop

This Java program allows the user to enter any integer value. Next, this Java program displays all the Prime numbers from 1 to 100 using For Loop.

TIP: Please refer Java Program to Check Prime Number article in Java to understand the steps involved in checking Prime Number

// Java Program to Print Prime Numbers from 1 to N
public class PrintPrimeNumbers1 {

	public static void main(String[] args) 
	{
		int i, number, count; 
		
		System.out.println(" Prime Numbers from 1 to 100 are : ");	
		for(number = 1; number <= 100; number++)
		{
			count = 0;
		    for (i = 2; i <= number/2; i++)
		    {
		    	if(number % i == 0)
		    	{
		    		count++;
		    		break;
		    	}
		    }
		    if(count == 0 && number != 1 )
		    {
		    	System.out.print(number + " ");
		    }  
		}
	}
}

Java Program to Print Prime Numbers from 1 to 100 using While Loop

This Java program returns the list of prime numbers from 1 to 100 using While Loop.

// Java Program to Print Prime Numbers from 1 to N
public class PrintPrimeNumbers2 {

	public static void main(String[] args) 
	{
		int i, number = 1, count; 
		
		System.out.println(" Prime Numbers from 1 to 100 are : ");	
		while(number <= 100)
		{
			count = 0;
			i = 2;
		    while(i <= number/2 )
		    {
		    	if(number % i == 0)
		    	{
		    		count++;
		    		break;
		    	}
		    	i++;
		    }
		    if(count == 0 && number != 1 )
		    {
		    	System.out.print(number + " ");
		    }
		    number++;
		}
	}
}

We just replaced the For loop in the above example with the While loop. If you don’t understand the While Loop, please refer: WHILE LOOP

Java Program to display Prime Numbers from 1 to N using Method

This Java program is the same as the first example. Still, we separated the prime numbers logic and placed it in a separate method.

// Java Program to Print Prime Numbers between Minimum and Maximum
import java.util.Scanner;

public class PrintPrimeNumbers3 {
	private static Scanner sc;
	public static void main(String[] args) 
	{
		int number, minimum, maximum, i, count; 
		sc = new Scanner(System.in);
		
		System.out.print(" Please Enter the Minimum value : ");
		minimum = sc.nextInt();	
		
		System.out.print(" Please Enter the Maximum value : ");
		maximum = sc.nextInt();	
		
	
		System.out.println(" Prime Numbers from 1 to 100 are : ");	
		for(number = minimum; number <= maximum; number++)
		{
			count = 0;
		    for (i = 2; i <= number/2; i++)
		    {
		    	if(number % i == 0)
		    	{
		    		count++;
		    		break;
		    	}
		    }
		    if(count == 0 && number != 1 )
		    {
		    	System.out.print(number + " ");
		    }  
		}
	}
}