Java Program to Display Prime Numbers From 1 to N

In this post, we will learn to code the Java Program to Display Prime Numbers From 1 to N. Let’s understand Prime Numbers and How to Check Prime Numbers in Java Programming Language.

In a previous post, we will How to check whether a number is prime or not. Today, we will display all the prime numbers from 1 to N.

Now, let’s see the Java Program to Display Prime Numbers From 1 to N using For Loop.

Java Program to Display Prime Numbers From 1 to N

import java.util.*;

public class Main{
    
    public static boolean isPrime(int number){
        if(number == 1) return false;
        if (number == 2) {
            return true;
        }
        else {
          int count = 0;
            //logic
          for (int div = 2; div * div <= number ; div++) {
            if (number % div == 0) {
              count++;
            }
          }
          if(count > 0){
            return false;
          }
        }
        
        return true;
    }
    
    public static void main(String[] args){
        
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter the value of N :");
        int N = sc.nextInt();
        
        System.out.println("All Prime Numbers from 1 to "+N+" are :");
        for(int num = 1 ; num <= N ; num++){
            if(isPrime(num) == true){
                System.out.println(num);
            }
        }
    }
    
}

Output 1

Enter the value of N : 50

All Prime Numbers from 1 to 50 are :
2
3
5
7
11
13
17
19
23
29
31
37
41
43
47

Output 2

Enter the value of N : 11

All Prime Numbers from 1 to 11 are :
2
3
5
7
11

How Does This Program Works?

        Scanner sc = new Scanner(System.in);
        System.out.println("Enter the value of N :");
        int N = sc.nextInt();

In this program,we take the input of N from the user using the Scanner Class in Java. Then, we have created a for loop from 1 to N and checked if each number is prime or not and printed each prime number.

        System.out.println("All Prime Numbers from 1 to "+N+" are :");
        for(int num = 1 ; num <= N ; num++){
            if(isPrime(num) == true){
                System.out.println(num);
            }
        }

To understand the optimized way to check prime numbers in Java Programming Language check this, Java Program to Check Prime Number.

This is the Java Program to Print Prime Numbers From 1 to N using for loop.

Java Program to Print Prime Numbers From 1 to N using While Loop

import java.util.*;

public class Main{
    
    public static boolean isPrime(int number){
        if(number == 1) return false;
        if (number == 2) {
            return true;
        }
        else {
          int count = 0;
            //logic
          for (int div = 2; div * div <= number ; div++) {
            if (number % div == 0) {
              count++;
            }
          }
          if(count > 0){
            return false;
          }
        }
        
        return true;
    }
    
    public static void main(String[] args){
        
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter the value of N :");
        int N = sc.nextInt();
        
        System.out.println("All Prime Numbers from 1 to "+N+" are :");
        int num=1;
        while(num <= N){
            if(isPrime(num) == true){
                System.out.println(num);
            }
            num++;
        }
    }
    
}

Output 1

Enter the value of N : 50

All Prime Numbers from 1 to 50 are :
2
3
5
7
11
13
17
19
23
29
31
37
41
43
47

Output 2

Enter the value of N : 11

All Prime Numbers from 1 to 11 are :
2
3
5
7
11

Conclusion

I hope after going through this post, you understand Java Program to Print Prime Numbers From 1 to N and learned to code a Java Program to Check Prime Number.

If you have any doubt regarding the topic, feel free to contact us in the comment section. We will be delighted to help you.

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