Question

I am wondering is there a better way to change a dictionary key, for example:

var dic = new Dictionary<string, int>();
dic.Add("a", 1);

and later on I decided to make key value pair to be ("b" , 1) , is it possible to just rename the key rather than add a new key value pair of ("b",1) and then remove "a" ?

Answer 1

No, you cannot rename keys once that have been added to a Dictionary. If you want a rename facility, perhaps add your own extension method:

public static void RenameKey<TKey, TValue>(this IDictionary<TKey, TValue> dic,
                                      TKey fromKey, TKey toKey)
{
  TValue value = dic[fromKey];
  dic.Remove(fromKey);
  dic[toKey] = value;
}