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    <p>Yes, MadMurf points out the most important difference: reachability checking at compile-time. The standard idiom would catch something like this and rightfully prevent it from compiling:</p> <pre><code> try { } catch (IndexOutOfBoundsException iooe) { } catch (ArrayIndexOutOfBoundsException aiooe) { } </code></pre> <p>The if/instanceof analog proposed in the original question would compile (which is NOT what you'd want because it's erroneous).</p> <p>The reason why the standard idiom catches the error at compile time is given in <a href="http://java.sun.com/docs/books/jls/third_edition/html/statements.html#14.21" rel="noreferrer">JLS 14.21 Unreachable Statements</a>.</p> <blockquote> <ul> <li>A catch block C is reachable iff both of the following are true: <ul> <li>[...]</li> <li>There is no earlier catch block A in the try statement such that the type of C's parameter is the same as or a subclass of the type of A's parameter.</li> </ul></li> </ul> </blockquote> <p>To further illustrate the point, the following compiles:</p> <pre><code> try { } catch (Exception e) { if (e instanceof Exception) { } else if (e instanceof Exception) { } } </code></pre> <p>As you can see, this "pokemon catching" idiom is much harder to maintain because it circumvents some of the compile-time reachability check enforced in the standard idiom.</p> <p>To make the point even more clear, whether you did it on purpose or not, you actually rearranged the order in which you checked the exceptions in your original question, a fact that could have easily been missed by others. If SubSubException is a subclass of SubException, the second if condition will NEVER be evaluated, and its body is effectively unreachable code.</p> <p>The if/instanceof approach is VERY prone to mistakes.</p>
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    1. COOthers have made valid points, but this is the best answer. As programmers we should never be doing work that the compiler can do for us.
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    2. CO+1 for using pokemon terminology
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