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What is the difference between null and undefined in JavaScript?
I want to know what the difference is between null and undefined in JavaScript.
33 Answers
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IntelliJ inspection gives “Cannot resolve symbol” but still compiles code
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First of all you should try File | Invalidate Caches and if it doesn't help, delete IDEA system directory. Then re-import the Maven project and see if it helps.
In some weird cases compiled classes may report wrong info and confuse IDEA. Verify that the classes from this jar r...
Entity Framework and Connection Pooling
...ecently started to use the Entity Framework 4.0 in my .NET 4.0 application and am curious about a few things relating to pooling.
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How to have TFS 2010 detect changes done to files outside of Visual Studio?
...le you're working outside of Visual Studio, it's probably best to go ahead and check the file out before editing it, either using the tf command line client, or using the Windows Explorer shell integration that's available in the TFS Power Tools release. (Plus an increasing number of other tools ha...
CASCADE DELETE just once
... with the ON DELETE CASCADE rule. Is there any way I can perform a delete and tell Postgresql to cascade it just this once? Something equivalent to
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What exactly does a jar file contain?
As an intern, I use company code in my projects and they usually send me a jar file to work with. I add it to the build path in Eclipse and usually all is fine and dandy.
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Defining a HTML template to append using JQuery
...of a templating engine in your project, such as:
mustache
underscore.js
handlebars
If you don't want to include another library, John Resig offers a jQuery solution, similar to the one below.
Browsers and screen readers ignore unrecognized script types:
<script id="hidden-template" type="...
Python str vs unicode types
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unicode is meant to handle text. Text is a sequence of code points which may be bigger than a single byte. Text can be encoded in a specific encoding to represent the text as raw bytes(e.g. utf-8, latin-1...).
Note that unicode is not encoded! T...
Accessing dict keys like an attribute?
... Unless - of course - you assign some value to them, see below)
Attributes and items are always in sync
Trying to access non-existent key as an attribute correctly raises AttributeError instead of KeyError
Supports [Tab] autocompletion (e.g. in jupyter & ipython)
Cons:
Methods like .keys() wil...
How do you stash an untracked file?
I have changes to a file, plus a new file, and would like to use git stash to put them away while I switch to another task. But git stash by itself stashes only the changes to the existing file; the new file remains in my working tree, cluttering up my future work. How do I stash this untracked fi...