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How to concatenate twice with the C preprocessor and expand a macro as in “arg ## _ ## MACRO”?
...ssing token (see below), is
replaced by the corresponding argument after all macros contained therein have been
expanded. Before being substituted, each argument’s preprocessing tokens are
completely macro replaced as if they formed the rest of the preprocessing file; no other
preprocessin...
Retrieve only the queried element in an object array in MongoDB collection
...r to filter an array during projection, which has the benefit of including all matches, instead of just the first one.
db.test.aggregate([
// Get just the docs that contain a shapes element where color is 'red'
{$match: {'shapes.color': 'red'}},
{$project: {
shapes: {$filter: {
...
Equals(=) vs. LIKE
...tify an example where these operators produce obviously different results. Allow me to quote from the MySQL manual:
Per the SQL standard, LIKE performs matching on a per-character basis, thus it can produce results different from the = comparison operator:
mysql> SELECT 'ä' LIKE 'ae' COLLA...
How do you round a floating point number in Perl?
.... For rounding to a certain number of digits, sprintf() or printf() is usually the easiest
route.
printf("%.3f", 3.1415926535); # prints 3.142
The POSIX module (part of the standard Perl distribution) implements
ceil(), floor(), and a number of other mathematical and trigonometric
func...
C library function to perform sort
...
qsort() is the function you're looking for. You call it with a pointer to your array of data, the number of elements in that array, the size of each element and a comparison function.
It does its magic and your array is sorted in-place. An example follows:
#include <st...
What is the difference between Θ(n) and O(n)?
...e of the algorithm as n gets larger is at most proportional to g(n).
Normally, even when people talk about O(g(n)) they actually mean Θ(g(n)) but technically, there is a difference.
More technically:
O(n) represents upper bound. Θ(n) means tight bound.
Ω(n) represents lower bound.
...
What are the advantages of NumPy over regular Python lists?
... Python objects, at least 4 bytes per pointer plus 16 bytes for even the smallest Python object (4 for type pointer, 4 for reference count, 4 for value -- and the memory allocators rounds up to 16). A NumPy array is an array of uniform values -- single-precision numbers takes 4 bytes each, double-pr...
How do I localize the jQuery UI Datepicker?
I really need a localized dropdown calendar. An English calendar doesn't exactly communicate excellence on a Norwegian website ;-)
...
Questions every good Java/Java EE Developer should be able to answer? [closed]
...
+1 @Jon: I usually subscribe to the "no need to memorize details" school of thought, but if you don't even know the basic conceptual differences between those basic interfaces, then you're definitely not a good Java developer.
...
getMinutes() 0-9 - How to display two digit numbers?
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@user1063287 see here developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…
– shlgug
Feb 21 '19 at 16:11
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