Java program to Find whether number is Prime or Not

17 Responses to “Java program to Find whether number is Prime or Not”

1. ganesh shirole says:

   August 18, 2011 at 11:14 am

   nice web site for c, java source
   send vb projects please(airline resurvation system)
2. vishal says:

   May 5, 2012 at 11:56 pm

   very nice budy. thanxxxxxx
3. abdul says:

   July 17, 2012 at 9:15 pm

   Thanks sir.. Super website
4. Sheth Amit says:

   August 22, 2012 at 6:59 pm

   good working dude………..
5. SIVA says:

   December 27, 2012 at 6:23 pm

   import java.io.*;
   public class Usersfriendly
   {
   private static BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
   public static void main(String args[])throws IOException
   {
   int choice;
   do
   {
   System.out.println(“INPUT YOUR NUMBER”);
   int m = Integer.parseInt(stdin.readLine());
   System.out.println(“1.PRIME NUMBERS”);
   System.out.println(“2.REAL NUMBERS”);
   System.out.println(“EXIT FROM WIZARD”);
   System.out.println(“ENTER THE CHOSEN”);
   choice = Integer.parseInt(stdin.readLine());
   switch(choice);

   {
   case1:
   int flag=0;
   for(i=2;i<m;i++)
   {
   if(m%i==0)
   {
   System.out.println(m+"IS NOT PRIME");
   flag=1;
   break;
   }
   }
   if(flag==0)
   System.out.println(m+"IS PRIME!");

   case2:
   flag=0;
   {
   if(m%2==0)
   {
   System.out.println(m+"IS EVEN");
   flag=1;
   break;
   }
   }

   if(flag==0)
   System.out.println(m+"IS ODD")
   }
   case 3:break;
   default: System.out.println("ERRORRRR!");
   while (choice!=3);
   }

   }
   }
   any mistake in this program ?
   pls give suggestions!
6. poornima says:

   January 30, 2013 at 3:48 pm

   Hi,
   After switch u had a ‘;’
   case should be followed by a blank space
   n should be declared
   and you used an adiitional } in case 2
   while should be written after a {
   try it after modifying these.
7. poornima says:

   January 30, 2013 at 4:00 pm

   Hi,
   After switch u had a ‘;’
   case should be followed by a blank space
   n should be declared
   and you used an adiitional } in case 2
   while should be written after the }
   try it after modifying these.
8. abhida says:

   June 20, 2013 at 9:01 pm

   Great helpg buddyzzzzz…… thnx yar…..
9. jaya prakash says:

   August 16, 2013 at 7:10 pm

   hi abitha wat dng
10. jaya prakash says:

    August 16, 2013 at 7:11 pm

    you name s sexy
11. Simple says:

    September 3, 2013 at 4:39 pm

    Simple and Esay
12. Code Nirvana says:

    October 21, 2013 at 10:01 pm

    Here’s my way:
    class PrimeNo
    {
    public static void main(String args[])
    {
    int num = Integer.parseInt(args[0]);
    int flag=0;
    for(int i=2;i< num;i++)
    {
    if(num%i==0)
    {
    System.out.println(num+" is not a Prime Number");
    flag = 1;
    break;
    }
    }
    if(flag==0)
    System.out.println(num+" is a Prime Number");
    }
    }

    MORE @ http://www.codenirvana.in/2013/04/how-to-check-prime-number-in-java.html
13. Jyothi says:

    November 1, 2013 at 9:51 am

    hai thank you program and wat happend if we use any other variable other than flag?
14. Code NIrvana says:

    November 12, 2013 at 5:50 pm

    Easier way to check prime number in JAVA :
    http://www.codenirvana.in/2013/04/how-to-check-prime-number-in-java.html
15. java2novice says:

    November 18, 2013 at 3:33 pm

    very nice. for more java examples visit java2novice.com site
16. rehaan says:

    November 21, 2013 at 1:57 pm

    thnx 4 nothin coz dis programm is gvn
    “Exception in thread “main” java.lang.ArrayIndexOutOfBoundsException: 0
    at primeno.main(primeno.java:7)
    “
17. coopX12 says:

    February 2, 2014 at 11:56 am

    It can be done in a much much easy way:

    import java.io.*;
    class PrimeOrNot
    {
    public static void main() throws IOException
    {
    InputStreamReader ir = new InputStreamReader(System.in);
    BufferedReader br = new BufferedReader(ir);
    System.out.println(“Enter the number”);
    double n = Double.parseDouble(br.readLine());
    System.out.println();
    int k, l=0;
    for (k=1; k<=n; k++)
    {
    if(n%k==0)
    {
    l=l+1;
    }
    }
    if(l==2)
    {
    System.out.println();
    System.out.println(n+" is a prime number");
    }
    else
    {
    System.out.println();
    System.out.println(n+" is NOT a prime number");
    }
    }
    }

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