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What is the point of interfaces in PHP?

...e. Most of the problems with multiple inheritance don't apply to abstract base classes, so most modern languages these days disable multiple inheritance yet call abstract base classes interfaces and allows a class to "implement" as many of those as they want. ...
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What is an API key? [closed]

...ccess control. For example, you can restrict access to certain API actions based on who's performing the request. For companies which make money from selling such services, it's also a way of tracking who's using the thing for billing purposes. Further still, by blocking a key, you can partially pre...
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What are the differences between LinearLayout, RelativeLayout, and AbsoluteLayout?

...n align views one by one (vertically/ horizontally). RelativeLayout means based on relation of views from its parents and other views. ConstraintLayout is similar to a RelativeLayout in that it uses relations to position and size widgets, but has additional flexibility and is easier to use in the ...
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Case in Select Statement

...earched CASE expression allows for values to be replaced in the result set based on comparison values. The following example displays the list price as a text comment based on the price range for a product. USE AdventureWorks2012; GO SELECT ProductNumber, Name, "Price Range" = CASE ...
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Difference Between One-to-Many, Many-to-One and Many-to-Many?

...ps that you need to be concerned with when mapping. The first category is based on multiplicity and it includes three types: *One-to-one relationships. This is a relationship where the maximums of each of its multiplicities is one, an example of which is holds relationship between Employee and P...
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`static` keyword inside function?

... static $cache = null; if ($cache === null) { $cache = '%heavy database stuff or something%'; } // code using $cache } In this example, the if would only be executed once. Even if multiple calls to doStuff would occur. ...
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Paperclip::Errors::MissingRequiredValidatorError with Rails 4

...s_attachment_content_type in Model Rails 3 class User < ActiveRecord::Base attr_accessible :avatar has_attached_file :avatar, :styles => { :medium => "300x300>", :thumb => "100x100>" }, :default_url => "/images/:style/missing.png" validates_attachment_content_type :avatar, :co...
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belongs_to through associations

... You can also delegate: class Company < ActiveRecord::Base has_many :employees has_many :dogs, :through => :employees end class Employee < ActiveRescord::Base belongs_to :company has_many :dogs end class Dog < ActiveRecord::Base belongs_to :employee deleg...
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Sending JWT token in the headers with Postman

I'm testing an implementation of JWT Token based security based off the following article . I have successfully received a token from the test server. I can't figure out how to have the Chrome POSTMAN REST Client program send the token in the header. ...
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Load dimension value from res/values/dimension.xml from source code

...etrieve a dimensional for a particular resource ID. Unit conversions are based on the current DisplayMetrics associated with the resources. so if you want exact dp value just as in xml just divide it with DisplayMetrics density int dp = (int) (getResources().getDimension(R.dimen.test) / getReso...