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Are Javascript arrays sparse?
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Yes, they are. They are actually hash tables internally, so you can use not only large integers but also strings, floats, or other objects. All keys get converted to strings via toString() before being added to the hash. You can confirm this with some test code:
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Difference between filter and filter_by in SQLAlchemy
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These code examples are misleading: Declarative base table classes and instances have neither filter nor query methods; they use the session.
– Turtles Are Cute
Mar 16 '16 at 19:45
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Common elements comparison between 2 lists
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+1 but personally I'd used frozenset as it's immutable and so can be used as dictionary key etc
– zebrabox
May 19 '10 at 11:04
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jQuery templating engines [closed]
...ox they all seem to break down in IE7 when it comes down to rendering HTML tables.
18 Answers
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Can I create more than one repository for github pages?
...ur io repo, create an index.html file on your master branch that acts as a table of contents linking to your other sites(subDirectories) index.html files. The username.github.io master branch seems to be the landing page that enables the hosting, so if it doesn't see an index file linking out to you...
Getting key with maximum value in dictionary?
...th item>
Returned values will be compared.
Dict
Python dict is a hash table. A key of dict is a hash of an object declared as a key. Due to performance reasons iteration though a dict implemented as iteration through it's keys.
Therefore we can use it to rid operation of obtaining a keys list.
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Rails extending ActiveRecord::Base
...like this idea because is a standard way of doing it but... I get an error Table 'moboolo_development.abstract_models' doesn't exist: SHOW FIELDS FROM abstract_models. Where should I put it?
– xpepermint
Feb 25 '10 at 7:59
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Virtual member call in a constructor
...y are constructed, but start out as the most derived type, with the method table being for the most derived type. This means that virtual method calls always run on the most derived type.
When you combine these two facts you are left with the problem that if you make a virtual method call in a cons...
How to check if a String contains another String in a case insensitive manner in Java?
...2446 ms
Regexp: 7180 ms
Regexp with cached Pattern: 1845 ms
Results in a table:
RELATIVE SPEED 1/RELATIVE SPEED
METHOD EXEC TIME TO SLOWEST TO FASTEST (#1)
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Is it possible to GROUP BY multiple columns using MySQL?
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Yes, you can group by multiple columns. For example,
SELECT * FROM table
GROUP BY col1, col2
The results will first be grouped by col1, then by col2. In MySQL, column preference goes from left to right.
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