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What does “program to interfaces, not implementations” mean?
...t worried about implementation and the interface signature determines what all operations can be done. This can be used to change the behavior of a program at run-time. It also helps you to write far better programs from the maintenance point of view.
Here's a basic example for you.
public enum La...
Difference between Array and List in scala
...at you should (probably) be using it much more than an Array (which is actually mutable - the immutable analog of Array is IndexedSeq).
If you are coming from a Java background, then the obvious parallel is when to use LinkedList over ArrayList. The former is generally used for lists which are only...
Creating stored procedure and SQLite?
...than in a separate SQL engine process. So it makes more sense to implement all your business logic including what would have been SP code in the host language.
You can however extend SQLite with your own user defined functions in the host language (PHP, Python, Perl, C#, Javascript, Ruby etc). You ...
Getting MAC Address
... says that it will return a random long if it fails to detect the mac: "If all attempts to obtain the hardware address fail, we choose a random 48-bit number with its eighth bit set to 1 as recommended in RFC 4122." So check that eighth bit!
– deinonychusaur
Fe...
What's the difference between belongs_to and has_one?
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They essentially do the same thing, the only difference is what side of the relationship you are on. If a User has a Profile, then in the User class you'd have has_one :profile and in the Profile class you'd have belongs_to :user. To det...
Creating my own Iterators
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/EDIT: I see, an own iterator is actually necessary here (I misread the question first). Still, I'm letting the code below stand because it can be useful in similar circumstances.
Is an own iterator actually necessary here? Perhaps it's sufficient to forward ...
How do I detect whether a Python variable is a function?
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If this is for Python 2.x or for Python 3.2+, you can also use callable(). It used to be deprecated, but is now undeprecated, so you can use it again. You can read the discussion here: http://bugs.python.org/issue10518. You can do this with:
callable(obj)
If this is for Python 3.x but ...
Getting URL hash location, and using it in jQuery
...te that this property already contains the # symbol at the beginning.
Actually you don't need the :first pseudo-selector since you are using the ID selector, is assumed that IDs are unique within the DOM.
In case you want to get the hash from an URL string, you can use the String.substring method:...
How to center the content inside a linear layout?
I'm trying to center an ImageView inside a LinearLayout horizontally and vertically, but I just can't do it.
The main reason why I'm not using a RelativeLayout for that is because I need the layout_weight (my Activity consists of four columns that should be equally divided, and also respon...
Is there any way to use a numeric type as an object key?
...in an object, it always gets converted to a string. Is there anyway to actually get it to store as a numeric? The normal typecasting does not seem to work.
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