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Ruby: Easiest Way to Filter Hash Keys?
...with just the choices in it.
choices = params.select { |key, value| key.to_s.match(/^choice\d+/) }
or you can use delete_if and modify the existing Hash e.g.
params.delete_if { |key, value| !key.to_s.match(/choice\d+/) }
or if it is just the keys and not the values you want then you can do:
p...
PostgreSQL create table if not exists
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CREATE TABLE myschema.mytable (i integer);
END IF;
END
$func$;
Call:
SELECT create_mytable(); -- call as many times as you want.
Notes:
The columns schemaname and tablename in pg_tables are case-sensitive. If you double-quote identifiers in the CREATE TABLE statement, you need ...
Is there a UIView resize event?
...ervingBounds() {
boundsObservation = observe(\.bounds) { capturedSelf, _ in
// ...
}
}
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Boost Statechart vs. Meta State Machine
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As there seems to be much interest, please allow me to give my (obviously biased) opinion, which should therefore be taken with a grain of salt:
MSM is much faster
MSM requires no RTTI or anything virtual
MSM has a more complete UML2 support (for example internal tr...
reference assignment is atomic so why is Interlocked.Exchange(ref Object, Object) needed?
In my multithreaded asmx web service I had a class field _allData of my own type SystemData which consists of few List<T> and Dictionary<T> marked as volatile . The system data ( _allData ) is refreshed once in a while and I do it by creating another object called newData and fill...
Replace tabs with spaces in vim
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What this all means, is nicely explained on the Vim wiki.
– Serge Stroobandt
Dec 11 '16 at 1:43
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How to fix Git error: object file is empty?
... the .git directory and run find . -type f -empty -delete -print to remove all empty files. Eventually git started telling me it was actually doing something with the object directories:
nathanvan@nathanvan-N61Jq:~/workspace/mcmc-chapter$ git fsck --full
Checking object directories: 100% (256/256)...
How can I reverse a NSArray in Objective-C?
...ne. If I see a method that returns an immutable object, I expect it to actually be returning an immutable object. Having it appear to return an immutable object but actual return a mutable object is a dangerous practice to get into.
– Christine
Jul 2 '12 at 22:...
How do I declare a 2d array in C++ using new?
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A dynamic 2D array is basically an array of pointers to arrays. You can initialize it using a loop, like this:
int** a = new int*[rowCount];
for(int i = 0; i < rowCount; ++i)
a[i] = new int[colCount];
The above, for colCount= 5 and rowCount =...
Is Using .NET 4.0 Tuples in my C# Code a Poor Design Decision?
...The consumer (not you) has to either guess or look up documentation, especially for things like Tuple<int, int>.
I would use them for private/internal members, but use result classes for public/protected members.
This answer also has some info.
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