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Python != operation vs “is not”

...right hand side and the left hand side are the very same object. No methodcalls are done, objects can't influence the is operation. You use is (and is not) for singletons, like None, where you don't care about objects that might want to pretend to be None or where you want to protect against object...
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String concatenation: concat() vs “+” operator

...then throwing it away when you create the final String. In practice memory allocation is surprisingly fast. Update: As Pawel Adamski notes, performance has changed in more recent HotSpot. javac still produces exactly the same code, but the bytecode compiler cheats. Simple testing entirely fails bec...
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'printf' vs. 'cout' in C++

...letely on operator overloading, so there is no issue with custom formats - all you do is define a subroutine taking std::ostream as the first argument and your type as second. As such, there are no namespace problems - as long you have a class (which isn't limited to one character), you can have wor...
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Date vs DateTime

... Unfortunately, not in the .Net BCL. Dates are usually represented as a DateTime object with the time set to midnight. As you can guess, this means that you have all the attendant timezone issues around it, even though for a Date object you'd want absolutely no timezone han...
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Greenlet Vs. Threads

... Greenlets provide concurrency but not parallelism. Concurrency is when code can run independently of other code. Parallelism is the execution of concurrent code simultaneously. Parallelism is particularly useful when there's a lot of work to be done in userspace, an...
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Java Desktop application: SWT vs. Swing [closed]

...ava library, no need for additional native libraries works the same way on all platforms Integrated GUI Editor in Netbeans and Eclipse good online tutorials by Sun/Oracle Supported by official java extensions (like java OpenGL) Cons Swing: Native look and feel may behave different from the real...
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PHP: exceptions vs errors?

... Exceptions are thrown - they are intended to be caught. Errors are generally unrecoverable. Lets say for instance - you have a block of code that will insert a row into a database. It is possible that this call fails (duplicate ID) - you will want to have a "Error" which in this case is an "Exc...
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What is the difference between typeof and instanceof and when should one be used vs. the other?

... @Luke generally a bad idea to use "new String" like this. that creates a "string object" rather than a string primitive. see section here developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/… – Colin D ...
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Dependency graph of Visual Studio projects

...pendteam the extra details and screenshots are OK. but since this is originally my answer, it looks like your edit somehow makes me I look like work at NDepend. Please add new answer with your edit, and also emphasize your new answer is addition to my answer. Thanks before :) –...
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static const vs #define

... Personally, I loathe the preprocessor, so I'd always go with const. The main advantage to a #define is that it requires no memory to store in your program, as it is really just replacing some text with a literal value. It also has...