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What is the difference between Gemfile and Gemfile.lock in Ruby on Rails
... say: "I want nokogiri as long as it’s greater than version 1.4.4", etc. Now suppose that I have set up my Gemfile 8 months ago and I successful setup my app with this requirement. 8 months ago nokogiri version was 1.4.4. My rails apps was running perfectly without any problems with this version.
...
What happens to C# Dictionary lookup if the key does not exist?
...corresponding value
}
else
{
// Key wasn't in dictionary; "value" is now 0
}
(Using ContainsKey and then the the indexer makes it look the key up twice, which is pretty pointless.)
Note that even if you were using reference types, checking for null wouldn't work - the indexer for Dictionary...
When to use ' (or quote) in Lisp?
...et (+ 3 2), + is then invoked on 3 and 2 yielding 5. Our original form is now (* 5 3) yielding 15.
Explain quote Already!
Alright. As seen above, all arguments to a function are evaluated, so if you would like to pass the symbol a and not its value, you don't want to evaluate it. Lisp symbols ca...
Getting the HTTP Referrer in ASP.NET
...able way of getting the browser's HTTP Referrer in ASP.Net ( C# ). I know the HTTP Referrer itself is unreliable, but I do want a reliable way of getting the referrer if it is present.
...
UICollectionView spacing margins
...
Now overriding the sectionInset method of subclassed UICollectionViewFlowLayout also has no effect. Setting property described below works.
– Dren
Apr 29 '15 at 15:37
...
Multiple inheritance/prototypes in JavaScript
...Update (2019): The original post is getting pretty outdated. This article (now internet archive link, since domain went away) and its associated GitHub library are a good modern approach.
Original post:
Multiple inheritance [edit, not proper inheritance of type, but of properties; mixins] in Javasc...
Is JavaScript's “new” keyword considered harmful?
...eof foo) )
return new foo();
// constructor logic follows...
}
Now you can have the advantages of new without having to worry about problems caused by accidentally misuse. You could even add an assertion to the check if the thought of broken code silently working bothers you. Or, as some...
Understanding $.proxy() in jQuery
...setTimeout($.proxy(function() {
$(this).addClass('aNewClass'); // Now "this" is again our element
}, this), 1000);
// ---^--------------and tell it that we want our DOM element to be the
// value of "this" in the function
});
So after we gave $.proxy() the f...
How do I set up NSZombieEnabled in Xcode 4?
...orting.
A typical case is when you over-release an object and you don't know which one:
With zombies: -[UITableView release]: message sent to deallocated instance
Without zombies:
This Xcode setting is ignored when you archive the application for App Store submission. You don't need to to...
How to remove constraints from my MySQL table?
...column to other tables columns. Mine had a standard name given to it. Also now I now that you can drop foreign keys safetely without the column itself being dropped
– Lealo
Aug 18 '17 at 0:35
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