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Why is the order in dictionaries and sets arbitrary?
...ash values are assigned to slots in a dynamic table (it can grow or shrink based on needs). And that mapping process can lead to collisions, meaning that a key will have to be slotted in a next slot based on what is already there.
Listing the contents loops over the slots, and so keys are listed in...
Entity framework linq query Include() multiple children entities
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Years later, I would not recommend the string-based includes, because they aren't runtime safe. If the navigation property name ever changes or is misspelled, it will break. Strongly suggest using the typed include instead.
– Jeff Putz
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Can enums be subclassed to add new elements?
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The reason I want to extend is because I'd like to have a base class called e.g. IntEnum, that looks like this: stackoverflow.com/questions/1681976/enum-with-int-value-in-java/…. Then all my enums could extend it...in this case just benefitting from inheritance and thus I wouldn'...
Design Patterns: Factory vs Factory method vs Abstract Factory
...family of objects that need to be of "the same kind", and have some common base classes. Here's a vaguely fruit-related example. The use case here is that we want to make sure that we don't accidentally use an OrangePicker on an Apple. As long at we get our Fruit and Picker from the same factory, th...
Two single-column indexes vs one two-column index in MySQL?
...nation of giver_id and recipient_id. Mind that index criteria is leftmost based - a query referring to only recipient_id would not be able to use the covering index in the statement I provided.
Additionally, MySQL can only use one index per SELECT so a covering index would be the best means of opt...
Nullable types and the ternary operator: why is `? 10 : null` forbidden? [duplicate]
... to an int?. Note that another possibility would be to box the int 10 to a base class or interface of System.Int32. As an example GetBoolValue() ? (IFormattable)10 : null // #1B or GetBoolValue() ? 10 : (IFormattable)null // #2B will be OK. This possibility may be a reason why they don't make the nu...
What is the difference between a pseudo-class and a pseudo-element in CSS?
...description
The pseudo-class concept is introduced to permit selection based on information that lies outside of the document tree or that cannot be expressed using the other simple selectors.
A pseudo-class always consists of a "colon" (:) followed by the name of the pseudo-class and optio...
adding noise to a signal in python
...ance .
When modeling this in python, you can either
1. Calculate variance based on a desired SNR and a set of existing measurements, which would work if you expect your measurements to have fairly consistent amplitude values.
2. Alternatively, you could set noise power to a known level to match som...
Maven project.build.directory
...t;project>
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<build>
<directory>${project.basedir}/target</directory>
<outputDirectory>${project.build.directory}/classes</outputDirectory>
<finalName>${project.artifactId}-${project.version}</finalName>
<testO...
How to remove all leading zeroes in a string
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Caveat $str := '0'. Addressed in my answer, based on this answer.
– Mike Weir
Dec 4 '15 at 3:58
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