Create SharePoint Web Application Programmatically

Generally web applications in SharePoint are created using the out-of-box functionality provided within Central Administration. But because of some client's needs there might be a requirement of creating these web applications within a custom utility solution. This functionality can be achieved programmatically using Microsoft SharePoint APIs. By this, one can easily create a web application & associate a content database to it, register the web application in the IIS server, create an associated application pool and define different credentials for the web aplication.

Example code using C#.Net     // Create  new object of SPWebApplication & SPWebApplicationBuilder class SPWebApplication newApplication; SPWebApplicationBuilder webAppBuilder = new SPWebApplicationBuilder(SPFarm.Local);   // Set necessary values to webAppBuilder object   webAppBuilder.Port = portNo; webAppBuilder.RootDirectory = new DirectoryInfo(D:\projects\TestWebSite3030); webAppBuilder.ApplicationPoolId = appPoolId; webAppBuilder.ApplicationPoolUsername = appPoolUserName; webAppBuilder.ApplicationPoolPassword = password; webAppBuilder.CreateNewDatabase = true;webAppBuilder.DatabaseServer = dbServerName; // DB server namewebAppBuilder.DatabaseName = dbName;// DB Name if (isSQLAuth) { webAppBuilder.DatabaseUsername = dbUid; // dbUid is username of the DB sever webAppBuilder.DatabasePassword = dbPwd; // dbpassword is password of the DB sever } webAppBuilder.UseNTLMExclusively = true;  // authentication provider for NTLM webAppBuilder.AllowAnonymousAccess = isAnonymous; // anonymous access permission   // Finally create web application newApplication = webAppBuilder.Create(); newApplication.Provision();