Question

write a java program to check prime number

Answer 1

public class prime
{
public static void main (int n)
{
int c=0;
for(int f=1;f<=n;f++)
{
if(n%f==0)
c++;
}
if(c==2)
System. out. println(''Prime number'') ;
else
System. out. println(''Not a prime number'') ;
}
}

Answer 2

CODE :

import java.util.*;

class prime

{

   public static void main(String args[])

   {

       Scanner sc=new Scanner(System.in);

       System.out.println("Enter a number to check whether the given number is prime number or not ");

       int n = sc.nextInt();

       int c = 0;

       for(int i=1;i<=n;i++)

       {

           if(n%i==0)

           {

               c++;

           }

       }

       if(c==2)

       {

           System.out.println("The entered number is a prime number");

       }

       else

       {

           System.out.println("The entered number is not a prime number");

       }

   }

}

Explanation:

A prime number has 2 factors .

Hence we run a for-loop and an if else statement to see the number of factors.

Then we can print the statements as necessary.