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copied!<p>You're running up against the difference between a reference type and a value type. </p> <p>Here's an <a href="http://msdn.microsoft.com/en-us/library/t63sy5hs(VS.80).aspx" rel="nofollow noreferrer">msdn article</a> on differences.</p> <p>A more descriptive answer would be that both are actually performing the same operation, the difference is that in the first example (the two integers) the assignment of mVar2 = mVar1 is assigning the value of mVar1 to mVar2, which is 1. However, in the case of the DataTable, what's actually being assigned is a memory location, not a DataTable.</p> <p>Say, for instance, that the DataTable you created resides in memory location 20. That would mean that the reference mVar1 would hold a reference to that location (20). When you do the assignment mVar2 = mVar1, you're telling mVar2 to hold the same value as mVar1, so mVar2 then references to memory location 20 as well. The result being that both variables reference the same DataTable.</p> <p>In order to achieve the behavior you're describing, you would indeed need to have a Copy ability, as you've stated. It would have to allocate an entirely new object, and copy the state of the previous object to the new one.</p> <p>For the DataTable class you could extend it like this inside an extension method:</p> <pre><code>public static DataTable Copy(this DatTable original) { var result = new DataTable(); //assume Property1 was a property of a DataTable result.Property1 = original.Property1; //continue copying state from original to result return result; } </code></pre>

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