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Is there a standard function to check for null, undefined, or blank variables in JavaScript?
...t undefined or null ? I've got this code, but I'm not sure if it covers all cases:
41 Answers
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Simple explanation of clojure protocols
...eployed, separately type checked. We want them to be type-safe. [Note: not all of these make sense in all languages. But, for example, the goal to have them type-safe makes sense even in a language like Clojure. Just because we can't statically check type-safety doesn't mean that we want our code to...
grep using a character vector with multiple patterns
...w. So its a compress way to output something like A1 | A2 so if one wanted all conditions then the collapse would be with an & sign, cool thanks.
– Ahdee
Feb 23 '18 at 15:41
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How do I update a Python package?
I'm running Ubuntu 9:10 and a package called M2Crypto is installed (version is 0.19.1). I need to download, build and install the latest version of the M2Crypto package (0.20.2).
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What is the difference between atomic / volatile / synchronized?
How do atomic / volatile / synchronized work internally?
7 Answers
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'Missing recommended icon file - The bundle does not contain an app icon for iPhone / iPod Touch of
... just need to drag and drop your 1024 x 1024 icon and the site will create all the icon sizes and send it to your email. Then follow the following method to set icons for iOS app.
After Apple launched iOS 8, iPhone 6 and 6 Plus, the app icon sizes and launch image sizes changed. Please visit my pos...
Java to Clojure rewrite
...ble state and develop pure (side-effect free) functions. You probably know all this already :-)
Anyway, this philosophy tends to lead towards something of a "bottom up" development style where you focus the initial efforts on building the right set of tools to solve your problem, then finally plug ...
What is the difference between pluck and collect in Rails?
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When you do:
User.first.gifts.collect(&:id)
You have objects with all fields loaded and you simply get the id thanks to the method based on Enumerable.
So:
if you only need the id with Rails 4, use ids: User.first.gifts.ids
if you only need some fields with Rails 4, use pluck: User.first...
Conditional Variable vs Semaphore
... that a piece of code is atomic, put a lock around it. You could theoretically use a binary semaphore to do this, but that's a special case.
Semaphores and condition variables build on top of the mutual exclusion provide by locks and are used for providing synchronized access to shared resources. ...
Why should we NOT use sys.setdefaultencoding(“utf-8”) in a py script?
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As per the documentation: This allows you to switch from the default ASCII to other encodings such as UTF-8, which the Python runtime will use whenever it has to decode a string buffer to unicode.
This function is only available at Python start-up time,...