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How to check if object has any properties in JavaScript?
...ws:
for(var prop in ad) {
if (ad.hasOwnProperty(prop)) {
// handle prop as required
}
}
It is important to use the hasOwnProperty() method, to determine whether the object has the specified property as a direct property, and not inherited from the object's prototype chain.
Edit
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What makes a keychain item unique (in iOS)?
...ws (derived from open source files from Apple, see Schema.m4, KeySchema.m4 and SecItem.cpp):
For a keychain item of class kSecClassGenericPassword, the primary key is the combination of
kSecAttrAccount and kSecAttrService.
For a keychain item of class kSecClassInternetPassword, the primary key is...
“Treat all warnings as errors except…” in Visual Studio
...0,1701,1702</WarningsNotAsErrors>
</PropertyGroup>
Note: 612 and 618 are both warnings about Obsolete, don't know the difference but the project i'm working on is reporting Obsolete with warning 618.
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How do I install from a local cache with pip?
...irtualenv environments. Is there a way that I can download a package once and then have pip install from a local cache?
...
In C# what is the difference between a destructor and a Finalize method in a class?
What is the difference, if there is one, between a destructor and a Finalize method in a class?
3 Answers
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How to avoid .pyc files?
... available
to Python programs as the
sys.dont_write_bytecode variable, and
Python code can change the value to
modify the interpreter’s behaviour.
Update 2010-11-27: Python 3.2 addresses the issue of cluttering source folders with .pyc files by introducing a special __pycache__ subfolder...
Difference between C++03 throw() specifier C++11 noexcept
Is there any difference between throw() and noexcept other than being checked at runtime and compile time, respectively?
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Difference between validate(), revalidate() and invalidate() in Swing GUI
...idate() marks the container as invalid. Means the content is somehow wrong and must be re-laid out. But it's just a kind of mark/flag. It's possible that multiple invalid containers must be refreshed later.
validate() performs relayout. It means invalid content is asked for all the sizes and all th...
What is the purpose of a stack? Why do we need it?
...the stack?
I assume you mean the evaluation stack of the MSIL language, and not the actual per-thread stack at runtime.
Why is there a transfer from memory to stack or "loading?" On the other hand, why is there a transfer from stack to memory or "storing"? Why not just have them all placed i...
Change case of a file on Windows?
... becomes SourceCode.java , for example. The catch: I'm on a Windows box, and the filesystem thinks those are the same file name.
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