How to iterate through Dictionary and change values?

Question

Dictionary myDict = new Dictionary();
//...
foreach (KeyValuePair kvp in myDict)
 {
     kvp.Value = Math.Round(kvp.Value,          


        

Answer 1

Loop through the keys in the dictionary, not the KeyValuePairs.

Dictionary<string, double> myDict = new Dictionary<string, double>();
//...
foreach (string key in myDict.Keys)
{
    myDict[key] = Math.Round(myDict[key], 3);
}

Answer 2

While iterating over the dictionary directly is not possible because you get an exception (like Ron already said), you don't need to use a temp list to solve the problem.

Instead use not the foreach, but a for loop to iterate through the dictionary and change the values with indexed access:

Dictionary<string, double> myDict = new Dictionary<string,double>();
//...    
for(int i = 0; i < myDict.Count; i++) {
    myDict[myDict.ElementAt(i).Key] = Math.Round(myDict.ElementAt(i).Value, 3);
}