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copied!<p>Generics provide performance and runtime-memory advantages over non-generic equivalents. For example, compare the following.</p> <pre><code>ArrayList arrayList = new ArrayList(new Byte[] { 1, 2, 3, 4, 5, 6, 7, 8} ); </code></pre> <p>vs</p> <pre><code>List<Byte> byteList = new List<Byte> { 1, 2, 3, 4, 5, 6, 7, 8 }; </code></pre> <p>The ArrayList will contain an internal storage of object[] which with each element pointing to a byte. The ideal memory for this part of the list with 32 bit pointers is therefore 8 * 4 + 8 = 40 bytes. I say ideal 'cause it's actually worse since the boxed bytes will have some additional overhead, although I don't know exactly how much. </p> <p>The List implementation will instead contain byte[] which will require just one pointer to the array plus the 8 bytes, for a total of 12 bytes of memory without the boxing overhead, whatever that is.</p> <p>In addition to the memory differences, there is also the performance cost of boxing/unboxing the values.</p> <p>The difference is less for reference types, but even there you'll have a cost penalty for casting constantly when taking data out of the non-generic type.</p> <p>These differences are real, but will have immeasurable impact on most applications. The real advantage of generics is greater reliability of compile-time verification and simpler code that results from using typed values.</p> <p>In my opinion it's best to use generics whenever appropriate and possible.</p> <p>Sam</p>

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