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The differences between .build, .create, and .create! and when should they be used?
...< 3.x
The most important part, however, is that these methods can be called through an association (has_many, etc.) to automatically link the two models.
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RSpec: describe, context, feature, scenario?
...
The context is an alias for describe, so they are functionally equivalent. You can use them interchangeably, the only difference is how your spec file reads. There is no difference in test output for example. The RSpec book says:
"We tend to use describe() for things and context...
When should I use the assets as opposed to raw resources in Android?
...older.
Since raw is a subfolder of Resources (res), Android will
automatically generate an ID for any file located inside it. This
ID is then stored in the R class that will act as a reference to
a file, meaning it can be easily accessed from other Android classes
and methods and even in Android XM...
Declaring variables inside loops, good practice or bad practice?
...their scope is restricted to inside the loop. It cannot be referenced nor called outside of the loop.
This way:
If the name of the variable is a bit "generic" (like "i"), there is no risk to mix it with another variable of same name somewhere later in your code (can also be mitigated using the -W...
What are the Web.Debug.config and Web.Release.Config files for?
... and you can create custom build configurations. A publish
profile typically corresponds to a destination environment.
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Revert a range of commits in git
...g for:
git revert B^..D
B^ means "the first parent commit of B": that allows to include B in the revert.
See "git rev-parse SPECIFYING REVISIONS section" which include the <rev>^, e.g. HEAD^ syntax: see more at "What does the caret (^) character mean?")
Note that each reverted commit is ...
Why are floating point numbers inaccurate?
...ted a lot like scientific notation: with an exponent and a mantissa (also called the significand). A very simple number, say 9.2, is actually this fraction:
5179139571476070 * 2 -49
Where the exponent is -49 and the mantissa is 5179139571476070. The reason it is impossible to represent some de...
IN vs OR in the SQL WHERE Clause
...ds a much more complex evaluation process than the IN construct because it allows many conditions, not only equals like IN.
Here is a like of what you can use with OR but that are not compatible with IN:
greater. greater or equal, less, less or equal, LIKE and some more like the oracle REGEXP_LIKE...
CSS filter: make color image with transparency white
...jP.gif" class="filter" />
</p>
First, brightness(0) makes all image black, except transparent parts, which remain transparent.
Then, invert(1) makes the black parts white.
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How to include layout inside layout?
...sing Layouts
Although Android offers a variety of widgets to provide small and
re-usable interactive elements, you might also need to re-use larger
components that require a special layout. To efficiently re-use
complete layouts, you can use the tag to embed another
layout inside the cu...