Question

I am working on some c# I have inherited.

I have a problem in that something is being repeated twice in the output, I think I have identified in the controller where this is being added;

if(!isDirectUK)
  rollingPriceSupp.Add(new KeyValuePair<string, float>("Personal Insurance",
                                                       (float)insuranceCost));
ViewData["vRollingPrice"] = rollingPriceSupp; 

How can I put a check at that point to see if the string “Personal Insurance” has already been added, so as to avoid it bieng repeated twice ?

Answer 1

You must add an

if(rollingPriceSupp.ContainsKey("Personal Insurance")) 

check prior to the Add method.

UPDATE: Since seeing the OPs comment, the List is implemented using a List<KeyValuePair> colletion. In this case the ContainsKey alone would not work.

From the question alone I figured that they use some kind of Hashtable collection. In this case the containsKey would be sufficient.
If you cannot change the implementation from List to a Hashtable, then the solution would be to iterate through the items and check if it contains the key. E.g.

bool bItemExists = false;
foreach(KeyValuePair<string, float> pItem in rollingPriceSupp)
{
   if(pItem.Key == "Personal Insurance")
   {
      bItemExists = true;
      break;
   }
}
if(!bItemExists)
{
    rollingPriceSupp.Add(new KeyValuePair<string, float>("Personal Insurance",
                                                       (float)insuranceCost));
}

That should do the trick for you. Not the most efficient solution perhaps but should work.