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How do you check if a variable is an array in JavaScript? [duplicate]
...me. Array.prototype, is actually an array. you can read more about it here https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray
variable instanceof Array
This method runs about 1/3 the speed as the first example. Still pretty solid, looks cleaner, if you'...
What's the difference between == and .equals in Scala?
...ou really need to find out if something is actually NaN use isNaN:
Java: https://docs.oracle.com/javase/7/docs/api/java/lang/Double.html#isNaN(double)
Scala: http://www.scala-lang.org/files/archive/api/2.11.8/index.html#scala.Double@isNaN():Boolean
...
What is a callback?
...n.
Throughout this process, the page is
live in the browser.
Source: http://msdn.microsoft.com/en-us/library/ms178208.aspx
If you are referring to callbacks in code:
Callbacks are often delegates to methods that are called when the specific operation has completed or performs a sub-action. Y...
Unicode, UTF, ASCII, ANSI format differences
...ldn't - but you need to distinguish between "content that is sent back via HTTP from the web server" and "content that is sent via email". It's not the web page content that sends the email - it's the app behind it, presumably. The web content would be best in UTF-8; the mail content could be in UTF...
What are the differences in die() and exit() in PHP?
...ection. exit() doesn't close the connection.
die():
<?php
header('HTTP/1.1 304 Not Modified');
die();
?>
exit():
<?php
header('HTTP/1.1 304 Not Modified');
exit();
?>
Results:
exit():
HTTP/1.1 304 Not Modified
Connection: Keep-Alive
Keep-Alive: timeout=5, max...
What is the meaning of “POSIX”?
...
But POSIX does not seem to specify the 128 + SIGNAL_ID rule used by Bash: https://unix.stackexchange.com/questions/99112/default-exit-code-when-process-is-terminated
Regular expression
There are two types: BRE (Basic) and ERE (Extended). Basic is deprecated and only kept to not break APIs.
Those...
Java `final` method: what does it promise?
...derived class, therefore it will do what the base class author intended.
http://download.oracle.com/javase/tutorial/java/IandI/final.html
Worth noting is the part where it suggests that methods called from constructors should be final.
...
Is Redis just a cache?
I have been reading some Redis docs and trying the tutorial at http://try.redis-db.com/ . So far, I can't see any difference between Redis and caching technologies like Velocity or the Enterprise Library Caching Framework
...
Make Visual Studio understand CamelCase when hitting Ctrl and cursor keys
...Options -> Editor -> Editor Behaviour is turned off.
Details here: http://davidrcook.wordpress.com/2009/11/05/working-with-camel-case-in-visual-studio/
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How to check the version before installing a package using apt-get?
...none)
Candidate: 2:2.8.4-2
Version table:
2:2.8.4-2 0
500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages
apt-get install -s <package-name>
$ apt-get install -s redis-server
NOTE: This is only a simulation!
apt-get needs root privileges for real ex...