title: Convert nullable double to double type datatype
body: <p>I have model class with lots of nullable double property in asp.net MVC 5 project</p>
  
  <pre><code>  public class ValueAddedTax
    {
      public int Id { get; set; }
      public double? TaxableGoodsSalePrice { get; set; }
      public double? TaxableGoodsSupplementaryDuty { get; set; }
      public double? TaxableGoodsValueAddedTax { get; set; }
      public double? ZeroRatedSalePrice { get; set; }
      public double? ZeroRatedSupplementaryDuty { get; set; }
      public double? ZeroRatedValueAddedTax { get; set; }
      public double? ExemptSalePrice { get; set; }
      public double? ExemptSupplementaryDuty { get; set; }
      public double? ExemptValueAddedTax { get; set; }
      public double? TotalTaxPayable { get; set; }
    }
  </code></pre>
  
  <p>now in controller I want to create local variable and try assign all the property data into it </p>
  
  <pre><code>    [HttpPost]
      [ValidateAntiForgeryToken]
      public ActionResult AddTaxInfo(ValueAddedTax valueAddedTax, int? id)
      {
          // Assagin Data
          double taxableGoodsSalePrice = valueAddedTax.TaxableGoodsSalePrice;
  
          if (!ModelState.IsValid)
          {
              if (valueAddedTax.CustomerInfoId != 0)
                  return RedirectToAction("ValueAddedTax", "Customer", new {id = valueAddedTax.CustomerInfoId});
  
              return RedirectToAction("Index", "Customer");
          }
     }
  </code></pre>
  
  <p>if any property value is null then i want them as 0 in local variable so that i can calculate.
  how can i do this??</p>