July 4, 2002 - A Web Service for Checking Prime Numbers | WebReference

July 4, 2002 - A Web Service for Checking Prime Numbers

Yehuda Shiran July 4, 2002
A Web Service for Checking Prime Numbers
Tips: July 2002

Yehuda Shiran, Ph.D.
Doc JavaScript

The following class defines the IsPrime Web service:

  <%@ WebService Language="JScript" class="PrimeNumbers" %>
  import System;
  import System.Web;
  import System.Web.Services;
  public class PrimeNumbers extends WebService {
    WebMethodAttribute public function IsPrime(n:int) : int {
      var i:int;
	  if (n % 2 == 0) return (n == 2);
	  if (n % 3 == 0) return (n == 3);
	  if (n % 5 == 0) return (n == 5);
	  for (i=7; i*i
A prime number is a number which is divisible only by itself and by 1. There are many algorithms around, and a lot of research has already been conducted on the subject. This is one of the algorithms. Simulate it on a piece of paper for a few examples, and prove to yourself that it works.

We have imported more namespaces than absolutely required (System.Web.Services). The two other namespaces above (System and System.Web) will be used in other Web services.

To learn more about JScript .NET, go to Column 112, JScript .NET, Part VI: Creating IE Web Services.