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Number of elements in a javascript object
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Although JS implementations might keep track of such a value internally, there's no standard way to get it.
In the past, Mozilla's Javascript variant exposed the non-standard __count__, but it has been removed with version 1.8.5.
For cross-browser scripting you're stuck with explicitly ite...
insert vs emplace vs operator[] in c++ map
...ing value_type or make_pair . While there is a lot of information about all of them and questions about particular cases, I still can't understand the big picture.
So, my two questions are:
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React.js - input losing focus when rerendering
I am just writing to text input and in onChange event i call setState , so React rerenders my UI. The problem is that the text input always lose a focus, so i need focus it again for each letter :D.
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When would I need a SecureString in .NET?
...-securestring .
We should remove encryption from SecureString across all platforms in .NET Core - We should obsolete SecureString - We probably shouldn't expose SecureString in .NET Core
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Immutable vs Mutable types
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Almost, but not exactly. Technically, all variables are passed by reference in Python, but have a semantics more like pass by value in C. A counterexample to your analogy is if you do def f(my_list): my_list = [1, 2, 3]. With pass-by-reference in C, the val...
Is there a standard way to list names of Python modules in a package?
Is there a straightforward way to list the names of all modules in a package, without using __all__ ?
10 Answers
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.NET HashTable Vs Dictionary - Can the Dictionary be as fast?
...d people talking about the generic advantages of the Dictionary which I totally agree with, which leads the boxing and unboxing advantage for a slight performance gain.
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Insert an element at a specific index in a list and return the updated list
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l.insert(index, obj) doesn't actually return anything. It just updates the list.
As ATO said, you can do b = a[:index] + [obj] + a[index:].
However, another way is:
a = [1, 2, 4]
b = a[:]
b.insert(2, 3)
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Create numpy matrix filled with NaNs
...r operations in numpy.
You can create an uninitialized array and assign to all entries at once:
>>> a = numpy.empty((3,3,))
>>> a[:] = numpy.nan
>>> a
array([[ NaN, NaN, NaN],
[ NaN, NaN, NaN],
[ NaN, NaN, NaN]])
I have timed the alternatives a[:] ...
How to print (using cout) a number in binary form?
...ter. FYI, casting doesn't work, the bitset variable is an object of some really arcane-looking bitset3ul (?!) class. Best to let the abstractions do the work!
– nirvanaswap
Mar 16 '16 at 5:39
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