How to Calculate students Rank based on the Total, If the Total amount repeated twice then the rank should be same

Question

Here what I tried :

  DataTable dt = new DataTable();
  dt.DefaultView.Sort = "ratio DESC";
  dt.Columns.Add(new DataColumn("Rank", typeof(int)));
  int count = 1;

  foreach (DataRowView dr in dt.DefaultView)
    {
      dr["Rank"] = count++;
    }

While I am looping it should check some condition, can any one help me ?

Answer 1

You need to access previous row value while looping. Go with traditional for loop. Be careful for the first record as there will be previous row for it.

for( int i = 0; i < dt.DefaultView.Rows.Count; i++ )
{
    if( i > 0 )
    {
       // Compare with previous row using index
       if( dt.DefaultView.Rows[i]["ratio"] == dt.DefaultView.Rows[i-1]["ratio"])
       {
           dt.DefaultView.Rows[i]["Rank"] = count;
       }
      else
      {
          dt.DefaultView.Rows[i]["Rank"] = count++;
      }
    }
   else
   {
       dt.DefaultView.Rows[i]["Rank"] = count;
   } 

}