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When is null or undefined used in JavaScript? [duplicate]
...e DOM methods getElementById(), nextSibling(), childNodes[n], parentNode() and so on return null (defined but having no value) when the call does not return a node object.
The property is defined, but the object it refers to does not exist.
This is one of the few times you may not want to test fo...
Swift how to sort array of custom objects by property value
lets say we have a custom class named imageFile and this class contains two properties.
18 Answers
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Restore LogCat window within Android Studio
I have recently started to use Android Studio v0.1.1, And i can't seem to find LogCat... Is it gone? Or if not, how can I enable it?
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Installing PG gem on OS X - failure to build native extension
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Same error for me and I didn't experience it until I downloaded OS X 10.9 (Mavericks). Sigh, another OS upgrade headache.
Here's how I fixed it (with homebrew):
Install another build of Xcode Tools (typing brew update in the terminal will p...
Jenkins Host key verification failed
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Change to the jenkins user and run the command manually:
git ls-remote -h git@bitbucket.org:person/projectmarket.git HEAD
You will get the standard SSH warning when first connecting to a new host via SSH:
The authenticity of host 'bitbucket.org (20...
Failed to import new Gradle project: failed to find Build Tools revision *.0.0
When I boot up Android Studio and select "New Project..." and go through creating a new project, I get this popup error:
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Why is it important to override GetHashCode when Equals method is overridden?
...s equal, it is not necessary for them to be the same; this is a collision, and Equals will be called to see if it is a real equality or not.
In this case, it looks like "return FooId;" is a suitable GetHashCode() implementation. If you are testing multiple properties, it is common to combine them ...
How do I install a module globally using npm?
I recently installed Node.js and npm module on OSX and have a problem with the settings I think:
7 Answers
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Java; String replace (using regular expressions)?
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Couple problems: \^ needs to be \\^ and $ needs to be \$.
– cdmckay
Mar 10 '09 at 21:00
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What does PHP keyword 'var' do?
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It's for declaring class member variables in PHP4, and is no longer needed. It will work in PHP5, but will raise an E_STRICT warning in PHP from version 5.0.0 up to version 5.1.2, as of when it was deprecated. Since PHP 5.3, var has been un-deprecated and is a synonym for 'pu...