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StringBuilder vs String concatenation in toString() in Java

...it is shorter and the compiler will in fact turn it into version 2 - no performance difference whatsoever. More importantly given we have only 3 properties it might not make a difference, but at what point do you switch from concat to builder? At the point where you're concatenating in a...
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Do subclasses inherit private fields?

...its not there. However. This is different than the notion of inheritance for a class. As is the case in the java world, where there is a question of semantics the arbiter is the Java Language Specification (currently 3rd edition). As the JLS states (https://docs.oracle.com/javase/specs/jls/se8/h...
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“implements Runnable” vs “extends Thread” in Java

...u to keep your work only loosely coupled with your choice of concurrency. For example, if you use a Runnable and decide later on that this doesn't in fact require it's own Thread, you can just call threadA.run(). Caveat: Around here, I strongly discourage the use of raw Threads. I much prefer the...
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Are Javascript arrays sparse?

...rally fall back to a sparse implementation - most likely the same one used for property access of regular objects - if using an actual array would be inefficient. You'll have to ask someone with more knowledge about specific implementations to answer what excatly triggers the shift from dense to sp...
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What killed my process and why?

... /var/log/kern.log contained a lot of info about the termination. -Thanks for the pointer. – sbq Apr 7 '09 at 17:49 7 ...
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What does the C++ standard state the size of int, long type to be?

I'm looking for detailed information regarding the size of basic C++ types. I know that it depends on the architecture (16 bits, 32 bits, 64 bits) and the compiler. ...
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Design Patterns: Abstract Factory vs Factory Method

...ne method of types it produces. (This is complicated refer to next diagram for better real-life example). Example From The .NET Framework DbFactoriesProvider is a Simple Factory as it has no sub-types. The DbFactoryProvider is an abstract factory as it can create various related database objects...
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Get statistics for each group (such as count, mean, etc) using pandas GroupBy?

...is creates four count columns, but how to get only one? (The question asks for "an additional column" and that's what I would like too.) – Jaan Jul 22 '15 at 6:58 ...
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Unit tests vs Functional tests

...lding of a house. While this analogy isn't quite correct, we can extend it for the purposes of understanding the difference between unit and functional tests. Unit testing is analogous to a building inspector visiting a house's construction site. He is focused on the various internal systems of the ...
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ggplot with 2 y axes on each side and different scales

... I concur with Andreas - sometimes (such as now, for me) a client wants two sets of data on the same plot, and does not want to hear me talk about Plotting Theory. I either have to convince them to not want that anymore (not always a battle I want to wage), or tell them "t...