Selecting a Collection Class
.NET Framework 1.1
Be sure to choose your Collections class carefully. Using the wrong collection can restrict your use of the collection.
Consider the following questions:
- Do you need a sequential list where the element is typically discarded after its value is retrieved?
- Do you need to access the elements in a certain order, such as first-in-first-out, last-in-first-out, or randomly?
- Queue offers first-in-first-out access.
- Stack offers last-in-first-out access.
- The rest of the collections offer random access.
- Do you need to access each element by index?
- ArrayList and StringCollection offer access to their elements by the zero-based index of the element.
- Hashtable, SortedList, ListDictionary, and StringDictionary offer access to their elements by the key of the element.
- NameObjectCollectionBase and NameValueCollection offer access to their elements by either the zero-based index or the key of the element.
- Will each element contain one value, a combination of one key and one value, or a combination of one key and multiple values?
- Do you need to sort the elements differently from how they were entered?
- Hashtable sorts the elements by the hash code of the key.
- SortedList sorts the elements by the key, based on an IComparer implementation.
- ArrayList provides a Sort method that takes an IComparer implementation as a parameter.
- Do you need fast searches and retrieval of information?
- ListDictionary is faster than Hashtable for small collections (10 items or less).
- Do you need collections that accept only strings?
- StringCollection (based on IList) and StringDictionary (based on IDictionary) are in the System.Collections.Specialized namespace.