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How can I use map and receive an index as well in Scala?
Is there any List/Sequence built-in that behaves like map and provides the element's index as well?
8 Answers
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How do I create a variable number of variables?
...u can use dictionaries to accomplish this. Dictionaries are stores of keys and values.
>>> dct = {'x': 1, 'y': 2, 'z': 3}
>>> dct
{'y': 2, 'x': 1, 'z': 3}
>>> dct["y"]
2
You can use variable key names to achieve the effect of variable variables without the security ris...
In C++, what is a “namespace alias”?
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To possibly explain the downvotes, SO is not and never will be a replacement forv a good C++ textbook. The question you posed will be answered by any such book. And the SO "feature" of answering your own questions should not be used to provide paraphrases of such books....
Design for Facebook authentication in an iOS app that also accesses a secured web service
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I just dealt with this myself, and here's the part that bit me:
In your step 5... It's possible for a user to register for an account with you entirely separate from their Facebook ID, right? Then some other time they log in with Facebook.... And you just...
Primary key or Unique index?
At work we have a big database with unique indexes instead of primary keys and all works fine.
15 Answers
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Getting exact error type in from DbValidationException
...uation where I'm initializing my model in DatabaseInitializer() for EF 4.1 and get this annoying error "Validation failed for one or more entities. See 'EntityValidationErrors' property for more details." So, I go to this EntityValidationErrors and there is a field {System.Data.Entity.Validation....
How do I sort an observable collection?
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Sorting an observable and returning the same object sorted can be done using an extension method. For larger collections watch out for the number of collection changed notifications.
I have updated my code to improve performance (thanks to nawfal)...
How do I find duplicates across multiple columns?
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Duplicated id for pairs name and city:
select s.id, t.*
from [stuff] s
join (
select name, city, count(*) as qty
from [stuff]
group by name, city
having count(*) > 1
) t on s.name = t.name and s.city = t.city
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How do I run a terminal inside of Vim?
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Vim 8.1 now has a built in terminal that can be opened with the :term command. This provides much more complete integration with the rest of the Vim features.
I would definitely recommend screen for something like this. Vim is a text editor, not a shell.
I would use Ctrl+AS to split the current w...
How can I install MacVim on OS X?
...vim
Step 4. Run brew link macvim
You now have the latest versions of vim and macvim managed by brew. Run brew update && brew upgrade every once in a while to upgrade them.
This includes the installation of the CLI mvim and the mac application (which both point to the same thing).
I use t...