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.
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