Prime numbers can be generated using Java Program. Prime numbers are the numbers that have exactly two factors, the number itself and 1. For example, 3, 5, 7, 11, 13, 17, and 19 are all prime numbers. Today, we will learn how to generate a Prime Number in java.
Prime Number definition
A prime number is a number that can only be divided by 1 and itself. For example, the number 7 is prime because it can only be divided by 1 and 7.
The number 6 is not prime because it can be divided by 1, 2, 3 and 6. The number 2 is the only even prime number.
Prime Number algorithms
A prime number (or prime) is a natural number that has exactly two distinct natural number divisors: 1 and itself.
The number 1 is not considered prime, and the number 0 is not considered prime. A prime number is the largest possible number that is divisible only by 1 and itself. Primes play a central role in mathematics and number theory.
In fact, the study of prime numbers is one of the most important areas of mathematics. So how do we find prime numbers?
There are many different algorithms for finding prime numbers, but the most efficient algorithms are the Sieve of Eratosthenes and the Miller-Rabin primality test.
import java.util.Scanner;
a program to generate prime numbers upto nJava
import java.util.*;
class primeNos
{
public static void main(String args[])
{
Scanner sc = new Scanner(System.in);
int i,j,n,c;
System.out.println("Enter the number till which you want prime numbers");
n=sc.nextInt();
System.out.println("Prime numbers are :-");
for(i=2;i<=n;i++)
{
c=0;
for(j=1;j<=i;j++)
{
if(i%j==0)
{
c++;
}
}
if(c==2)
{
System.out.print(i+" ");
}
}
}
}
How to generate Prime Number in java
To generate a Prime number in Java, you will need to use the Java Prime Number Generator class. This class has a few methods that you can use to generate a Prime number.
The isPrime() method takes a number as input and checks whether that number is a Prime number. If it is, the method returns true.
The nextPrime() method returns the next Prime number after the given number. The generatePrimes() method generates a list of Prime numbers. You can use any of these methods to generate a Prime number.
The border between composite and prime
A prime number is a natural number that has only two distinct divisors, 1 and itself. Composite numbers are numbers that are not prime.
The first step in determining whether a number is prime is to check whether it is divisible by any number other than 1 and itself. If it is, then the number is not prime. However, determining whether a number is prime is more complicated than simply checking for divisibility.
The next step is to look at the number’s border between composite and prime. A number is prime if it has no factors other than 1 and itself. However, a number is composite if it has one or more factors that are not prime.
Test algorithm for composite
You can use the Sieve of Eratosthenes to determine whether a number is prime or composite. This algorithm starts with the number 2 and iterates through every number greater than 2, crossing out numbers that are divisible by any number in the set {2, 3, 4, 5, 6, 7, 8, 9, 10}. Any number that’s left is prime. You can use a for loop to test this algorithm.
Output
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
