IEnumerable<KeyValuePair<string, string>> implementation |
| Rune Funch Søltoft replied to Chris Falter at 25-Apr-08 04:02 |
The implementation with yield return could look like this
public static IEnumerable<KeyValuePair<string, string>> KeyValuePairs {
get {
MaritalStatus ms = new MaritalStatus(MaritalStatus.Married);
foreach (KeyValuePair<string, string> kvp in ms.LookupDict)
yield return kvp;
}
}
There's two main differences to the above implementation. It's documented more clearly that it's "readonly" there's no way to change the elements in the IEnumerable (unless u really try hard, figuring out the actual implementation, casting/using reflection and then ur on ur own :-) ) the second difference is that the implementation here use lazy evaluation.
writing code like:
var pairs = MaritalStatus.KeyValuePairs;
will not actually execute the foreach loop.
if u later write something like
var enumerator = pairs.GetEnumerator();
var firstKey = enumerator.MoveNext() ? enumerator.Current.Key : "not found";
u still havent iterated the entire LookupDict but only the first element
hope this clearify my point from the above post
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