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Use dynamic variable names in JavaScript
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Since ECMA-/Javascript is all about Objects and Contexts (which, are also somekind of Object), every variable is stored in a such called Variable- (or in case of a Function, Activation Object).
So if you create variables like this:
var a = 1,
b = 2,
c = 3;
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How to increment a NSNumber
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Update: FYI, I personally like BoltClock's and DarkDusts's one-line answers better. They're more concise, and don't require additional variables.
In order to increment an NSNumber, you're going to have to get its value, increment that, and store it in a new NSNumbe...
How does zip(*[iter(s)]*n) work in Python?
...unction call. Therefore you're passing the same iterator 3 times to zip(), and it pulls an item from the iterator each time.
x = iter([1,2,3,4,5,6,7,8,9])
print zip(x, x, x)
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Converting int to bytes in Python 3
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That's the way it was designed - and it makes sense because usually, you would call bytes on an iterable instead of a single integer:
>>> bytes([3])
b'\x03'
The docs state this, as well as the docstring for bytes:
>>> help(bytes)
...
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How do I write a correct micro-benchmark in Java?
How do you write (and run) a correct micro-benchmark in Java?
11 Answers
11
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C++ unordered_map using a custom class type as the key
... things:
A hash function; this must be a class that overrides operator() and calculates the hash value given an object of the key-type. One particularly straight-forward way of doing this is to specialize the std::hash template for your key-type.
A comparison function for equality; this is require...
Most efficient way to store thousand telephone numbers
...digits left. We view these remaining five digits as 17-bit binary integers and store k of those bits using one method and 17 - k = m with a different method, determining k at the end to minimize the required space.
We first sort the phone numbers (all reduced to 5 decimal digits). Then we count how...
Calculate a Running Total in SQL Server
...QL Server implementation of the Over clause is somewhat limited.
Oracle (and ANSI-SQL) allow you to do things like:
SELECT somedate, somevalue,
SUM(somevalue) OVER(ORDER BY somedate
ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW)
AS RunningTotal
FROM Table
SQL Server gi...
Inserting a PDF file in LaTeX
...ude, i.e. \includepdf[pages={1,3,5}]{myfile.pdf} would include pages 1, 3, and 5 of the file. To include the entire file, you specify pages={-}, where {-} is a range without the endpoints specified which default to the first and last pages, respectively.
– rcollyer
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What is an intuitive explanation of the Expectation Maximization technique? [closed]
... here.
Suppose we have some data sampled from two different groups, red and blue:
Here, we can see which data point belongs to the red or blue group. This makes it easy to find the parameters that characterise each group. For example, the mean of the red group is around 3, the mean of the blue...