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.net - How to iterate through Dictionary and change values?

Dictionary<string,double> myDict = new Dictionary();
//...
foreach (KeyValuePair<string,double> kvp in myDict)
 {
     kvp.Value = Math.Round(kvp.Value, 3);
}

I get an error: "Property or indexer 'System.Collections.Generic.KeyValuePair.Value' cannot be assigned to -- it is read only."
How can I iterate through myDict and change values?

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According to MSDN:

The foreach statement is a wrapper around the enumerator, which allows only reading from the collection, not writing to it.

Use this:

var dictionary = new Dictionary<string, double>();
// TODO Populate your dictionary here
var keys = new List<string>(dictionary.Keys);
foreach (string key in keys)
{
   dictionary[key] = Math.Round(dictionary[key], 3);
}

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