Prime Number Generator Logic

Question

I am supposed to make a class PrimeNumberGenerator which has a method nextPrime that will print out all prime numbers up to a number the user input

Answer 1

To generate prime number simply loop through a given number and check if that number is prime or not. For efficient prime number generation IsPrime method must be very efficient and fast. So here is code to check if given number is prime or not very efficiently.

public static boolean IsPrime(int n) {

    if (n > 2 && n %2 == 0){
        return false;
    }
    int top = (int)Math.sqrt(n)+1;
    for (int i=3;i

Here is the code that will generate prime number between 1 and given number.

 public class GeneratePrimeNumber {
    public static void main(String[] args) {
    System.out.println("Enter number to get prime number");
    int n = new Scanner(System.in).nextInt();
        for (int j=0;j