How to optimize a nested foreach loop which is creating same data object (with different values)

Question

I have following code which gets MastrSegments from repository(entity framework). It's working but I think I am violating DRY (though not sure).

MastrSegments conatins collection of SegReqs and SegReq contains collection Routes. And I am looping through them to update RootObject

 foreach (var MastrSegment in MastrSegments)
 {
 var segReqCount = MastrSegment.segReqs.Count();
 var MastrSegmentRow = new Row
 {
 c = new RootObject[] { new RootObject { v = MastrSegment.Name }, new RootObject { v = "TopClient" }, new RootObject { v = segReqCount }, new RootObject { v = 12 } }
 };
 foreach (var segReq in MastrSegment.segReqs)
 {
 var routesCount = segReq.routess.Count;
 Row segReqRow;
 if (segReq.Name != MastrSegment.Name)
 {
 segReqRow = new Row
 {
 c = new RootObject[] { new RootObject { v = segReq.Name }, new RootObject { v = MastrSegment.Name }, new RootObject { v = routesCount }, new RootObject { v = -26 } }
 };
 }
 else
 {
 throw new NotSupportedException("MastrSegment name and segReq name can not be same !!");
 }
 foreach (var routes in segReq.routess)
 {
 var circuitsCount = routes.Circuits.Count;
 Row routesRow = null;
 if (routes.Name != segReq.Name)
 {
 routesRow = new Row
 {
 c = new RootObject[] { new RootObject { v = routes.Name }, new RootObject { v = segReq.Name }, new RootObject { v = circuitsCount }, new RootObject { v = 16 } }
 };
 }
 else
 {
 throw new NotSupportedException("segReq name and routes name can not be same !!");
 }
 rows.Add(routesRow);
 }
 rows.Add(segReqRow);
 }
 rows.Add(MastrSegmentRow);
 }
 var returnData = rows.ToArray();

Answer 1

when ever you want to solve violations of the DRY principle you have to convert similar code into equal code.

If you look at the two inner loops: make the most inner loop using new local variables to replace the differeing parts

 {
 var circuitsCount = routes.Circuits.Count;
 Row routesRow = null;
 if (routes.Name != segReq.Name)
 {
 routesRow = new Row
 {
 c = new RootObject[] { new RootObject { v = routes.Name }, new RootObject { v = segReq.Name }, new RootObject { v = circuitsCount }, new RootObject { v = 16 } }
 };
 }
 else
 {
 throw new NotSupportedException("segReq name and routes name can not be same !!");
 }
 rows.Add(routesRow);
 }

becomes

 { // may be no valid syntax since I'm not a C# guy...
 var count = routes.Circuits.Count;
 Row routesRow = null;
 var master = "routes"
 var masterName = routes.Name;
 var detail = "segReq"
 var detailName = segReq.Name;
 var magicNumber = 16;
 if (masterName != detailName )
 {
 routesRow = new Row
 {
 c = new RootObject[] { new RootObject { v = masterName }, new RootObject { v = detailName }, new RootObject { v = count }, new RootObject { v = magicNumber } }
 };
 }
 else
 {
 throw new NotSupportedException(detail+" name and "+master+" name can not be same !!");
 }
 rows.Add(routesRow);
 }

now you extract the "future common" part to a new method:

 {
 var count = routes.Circuits.Count;
 var master = "routes"
 var masterName = routes.Name;
 var detail = "segReq"
 var detailName = segReq.Name;
 var = magicNumber 16;
 Row routesRow = CreateMasterDetailRow(master, masterName, detail, detailName, count, magicNumber);
 rows.Add(routesRow);
 }
//...
func Row CreateMasterDetailRow(var master, var masterName, var detail, var detailName, var count, var magicNumber)
{
 if (masterName != detailName )
 {
 return new Row
 {
 c = new RootObject[] { new RootObject { v = masterName }, new RootObject { v = detailName }, new RootObject { v = circuitsCount }, new RootObject { v = magicNumber } }
 };
 }
 else
 {
 throw new NotSupportedException(detail+" name and "+master+" name can not be same !!");
 } 
}

inline the extracted variables into the function call:

 {
 Row routesRow = CreateMasterDetailRow("routes", routes.Name, "segReq", segReq.Name, routes.Circuits.Count, 16);
 rows.Add(routesRow);
 }

then use the call in the middle loop:

 { // maybe I got the order of "master" and "detail" wrong...
 Row segReqRow= CreateMasterDetailRow("MastrSegment ", MastrSegment.Name, "segReq", segReq.Name, segReq.routess.Count, -26);
 foreach (var routes in segReq.routess)
 {
 Row routesRow = CreateMasterDetailRow("routes", routes.Name, "segReq", segReq.Name, routes.Circuits.Count, 16);
 rows.Add(routesRow);
 }
 rows.Add(segReqRow);

You can even replace the similar code in the outer loop if you provide some "fake data" for the (not failing) consistency check to satify the new methods parameter list...