How to iterate through keys and values of an `IDictionary`?

c# idictionary
Joseph Humfrey picture Joseph Humfrey · Mar 24, 2017 · Viewed 14.9k times · Source

How would I iterate through the keys and values of an IDictionary if I don't know the concrete types of the keys and values within, therefore want to just treat them as objects?

If I do something like:

foreach(var x in myIDictionary) { ... }

I think x is an object. But how would I get the Key and Value out of it (both typed as objects), as specified in the IDictionaryEnumerator? There isn't an IKeyValuePair without generic parameters is there?

I guess I could loop through the enumerator by hand using MoveNext etc, but I feel like there must be a way to do it with foreach!

Answer

Lanorkin picture Lanorkin · Mar 24, 2017

You can explicitly specify DictionaryEntry pair type in foreach like this:

foreach (DictionaryEntry x in myIDictionary)

Though you should be sure that it is standard implementation of IDictionary (like Hashtable or Dictionary<TKey, TValue>)

Otherwise it can be literally anything in enumerator.

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