How to get all SharePoint Web Applications from SP Farm programmatically using C# ?

Here is a way to get all SharePoint Web Applications in a SP Farm:

public ListItemCollection GetAllWebApplicationsInSPFarm()
{
ddlDataSource = new ListItemCollection();
SPSecurity.RunWithElevatedPrivileges(delegate()
{
SPServiceCollection services = SPFarm.Local.Services;
foreach (SPService curService in services)
{
if (curService is SPWebService)
{
webService = (SPWebService)curService;
if (curService.TypeName.Equals("Microsoft SharePoint Foundation Web Application"))
{
webService = (SPWebService)curService;
SPWebApplicationCollection webApplications = webService.WebApplications;
foreach (SPWebApplication webApplication in webApplications)
{
if (webApplication != null)
{
//Now you have the required object i.e. webApplication. You can use it like this:
//string webApp = webApplication.AlternateUrls[0].Collection.Name.ToString();
//Write your code here…    
}
}
}
}
}
});
}