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Checking if a key exists in a JavaScript object?
...r, if you want to particularly test for properties of the object instance (and not inherited properties), use hasOwnProperty:
obj.hasOwnProperty("key") // true
For performance comparison between the methods that are in, hasOwnProperty and key is undefined, see this benchmark
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How would you implement an LRU cache in Java?
...ructures would you use? I've already implemented one using LinkedHashMap and Collections#synchronizedMap , but I'm curious if any of the new concurrent collections would be better candidates.
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Threads vs Processes in Linux
...ter to use processes instead of threads, since Linux is very efficient in handling processes, and because there are so many problems (such as locking) associated with threads. However, I am suspicious, because it seems like threads could give a pretty big performance gain in some situations.
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Linux: compute a single hash for a given folder & contents?
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If there is a whole directory tree, you're probably better off using find and xargs. One possible command would be
find path/to/folder -type f -print0 | sort -z | xargs -0 sha1sum | sha1sum
And, finally, if you also need to take account of permissions and empty directories:
(find path/to/folde...
Python 3.x rounding behavior
I was just re-reading What’s New In Python 3.0 and it states:
11 Answers
11
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Math - mapping numbers
How do I map numbers, linearly, between a and b to go between c and d.
9 Answers
9
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“git pull” or “git merge” between master and development branches
I have my master branch and a develop branch for working on a few changes. I need to merge changes from master into develop , but will eventually merge everything from develop into master . I have two different workflows in mind:
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Creating a Pandas DataFrame from a Numpy array: How do I specify the index column and column headers
...g of a list of lists, representing a two-dimensional array with row labels and column names as shown below:
9 Answers
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is there an virtual environment for node.js?
...s is your main issue, then maybe consider using the very cool 'bundle' command with npm. This is closer to freezing gems or using bundler in rails, rather than rvm.
It's super easy. Just create a package.json file:
{ "name": "yourapp", "version": "0.0.1", "dependencies": {"jade": "0.4.1"}}
and t...
Window.open and pass parameters by post method
...rect, with encoding of values in the HTML code), just open an empty window and post a form to it.
Example:
<form id="TheForm" method="post" action="test.asp" target="TheWindow">
<input type="hidden" name="something" value="something" />
<input type="hidden" name="more" value="someth...