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Getting an object from an NSSet
...containsObject to test for membership, use anyObject to get a member (not random), or convert it to an array (in no particular order) with allObjects.
A set is appropriate when you don't want duplicates, don't care about order, and want fast membership testing.
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John Carmack's Unusual Fast Inverse Square Root (Quake III)
...code below. Can someone explain line by line what exactly is going on here and why this works so much faster than the regular implementation?
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Should the hash code of null always be zero, in .NET
...the same hash code.
Returning 0 or -1 for null, so long as you choose one and return it all the time, will work. Obviously, non-null hash codes should not return whatever value you use for null.
Similar questions:
GetHashCode on null fields?
What should GetHashCode return when object's identifie...
How can I avoid running ActiveRecord callbacks?
...
This solution is Rails 2 only.
I just investigated this and I think I have a solution. There are two ActiveRecord private methods that you can use:
update_without_callbacks
create_without_callbacks
You're going to have to use send to call these methods. examples:
p = Person.ne...
iOS difference between isKindOfClass and isMemberOfClass
What is the difference between the isKindOfClass:(Class)aClass and the isMemberOfClass:(Class)aClass functions?
I know it is something small like, one is global while the other is an exact class match but I need someone to specify which is which please.
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How to hide only the Close (x) button?
I have a modal dialog, and need to hide the Close (X) button, but I cannot use
ControlBox = false , because I need to keep the Minimize and Maximize buttons.
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Check if database exists in PostgreSQL using shell
...rows" will succeed. So we pipe this output through a bunch of built-in command line tools to only search in the first column.
The -t flag removes headers and footers:
my_db | my_user | UTF8 | en_US.UTF8 | en_US.UTF8 |
postgres | postgres | LATIN1 | en_US | en_US |
te...
Can HTML checkboxes be set to readonly?
...avascript prevents continuing the chain of execution for the click or key handler. Has nothing to do with the checkbox's state
– Jessica Brown
Aug 20 '11 at 2:03
9
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How do I disable text selection with CSS or JavaScript? [duplicate]
... edited Jun 1 '15 at 17:08
Andy
1,4461515 silver badges3333 bronze badges
answered Sep 23 '10 at 14:44
Je...
How to create a numpy array of all True or all False?
...s very easily:
e.g. numpy.ones((2, 2)) or numpy.zeros((2, 2))
Since True and False are represented in Python as 1 and 0, respectively, we have only to specify this array should be boolean using the optional dtype parameter and we are done.
numpy.ones((2, 2), dtype=bool)
returns:
array([[ True, ...