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Checking if a key exists in a JavaScript object?
...r, if you want to particularly test for properties of the object instance (and not inherited properties), use hasOwnProperty:
obj.hasOwnProperty("key") // true
For performance comparison between the methods that are in, hasOwnProperty and key is undefined, see this benchmark
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How to make good reproducible pandas examples
Having spent a decent amount of time watching both the r and pandas tags on SO, the impression that I get is that pandas questions are less likely to contain reproducible data. This is something that the R community has been pretty good about encouraging, and thanks to guides like this , newc...
What does the C++ standard state the size of int, long type to be?
...es.
I know that it depends on the architecture (16 bits, 32 bits, 64 bits) and the compiler.
24 Answers
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Different floating point result with optimization enabled - compiler bug?
The below code works on Visual Studio 2008 with and without optimization. But it only works on g++ without optimization (O0).
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How do I completely uninstall Node.js, and reinstall from beginning (Mac OS X)
My version of node is always v0.6.1-pre even after I install brew node and NVM install v0.6.19.
28 Answers
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Lock, mutex, semaphore… what's the difference?
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A lock allows only one thread to enter the part that's locked and the lock is not shared with any other processes.
A mutex is the same as a lock but it can be system wide (shared by multiple processes).
A semaphore does the same as a mutex but allows x number of threads to enter, this...
So, JSONP or CORS? [closed]
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This is a pretty broad question, and could warrant a wiki unto itself. There is also quite a bit on google regarding the two, but I think I can hit a few key points.
If you need a read-only ajax interface to your servers and you need to support IE<=9...
SQL Server query to find all permissions/access for all users in a database
...a specific database, or objects within the database such as tables, views, and stored procedures, either directly or due to roles, etc. This report would be used for security auditing purposes. Not sure if anyone has a query that will fit my needs completely, but hopefully something that will give...
What is this operator in MySQL?
I'm working on code written by a previous developer and in a query it says,
9 Answers
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REST Complex/Composite/Nested Resources [closed]
...is slightly more complex in that a cover really does require a comic book, and visa versa.
However, if you consider an email message as a resource, and the from address as a child resource, you can obviously still reference the from address separately. For example, get all from addresses. Or, creat...