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Extracting bits with a single multiplication
I saw an interesting technique used in an answer to another question , and would like to understand it a little better.
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Why is the Java main method static?
...ntire class - sometimes you have an instance that hasn't been initialized, and you have to check for it in every method that could be called.
There are just too many edge cases and ambiguities for it to make sense for the JVM to have to instantiate a class before the entry point is called. That's ...
When is SQLiteOpenHelper onCreate() / onUpgrade() run?
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SQLiteOpenHelper onCreate() and onUpgrade() callbacks are invoked when the database is actually opened, for example by a call to getWritableDatabase(). The database is not opened when the database helper object itself is created.
SQLiteOpenHelper versi...
Practical uses of git reset --soft?
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git reset is all about moving HEAD, and generally the branch ref.
Question: what about the working tree and index?
When employed with --soft, moves HEAD, most often updating the branch ref, and only the HEAD.
This differ from commit --amend as:
it doesn't cre...
What are the -Xms and -Xmx parameters when starting JVM?
Please explain the use of Xms and Xmx parameters in JVMs. What are the default values for them?
5 Answers
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What does “Could not find or load main class” mean?
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The java <class-name> command syntax
First of all, you need to understand the correct way to launch a program using the java (or javaw) command.
The normal syntax1 is this:
java [ <options> ] <class-name> [<arg> ...]
where &...
Reducing memory usage of .NET applications?
...memory footprint is all about demystifying the working set, process memory and how to perform accurate calculations on your total in-RAM consumption.
I will not say that you should ignore the memory footprint of your application -- obviously, smaller and more efficient does tend to be desirable. Ho...
.c vs .cc vs. .cpp vs .hpp vs .h vs .cxx [duplicate]
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Historically, the first extensions used for C++ were .c and .h, exactly like for C. This caused practical problems, especially the .c which didn't allow build systems to easily differentiate C++ and C files.
Unix, on which C++ has been developed, has case sensitive file systems....
What's the difference between emulation and simulation? [duplicate]
In simple understandable terms, what is the difference between the two terms?
10 Answers
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What are the advantages of using a schema-free database like MongoDB compared to a relational databa
I'm used to using relational databases like MySQL or PostgreSQL, and combined with MVC frameworks such as Symfony, RoR or Django, and I think it works great.
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