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Difference between variable declaration syntaxes in Javascript (including global variables)?
...gh in practical terms they're not usually big ones.
There's a fourth way, and as of ES2015 (ES6) there's two more. I've added the fourth way at the end, but inserted the ES2015 ways after #1 (you'll see why), so we have:
var a = 0; // 1
let a = 0; // 1.1 (new with ES2015)
const a = 0; //...
How can I call controller/view helper methods from the console in Ruby on Rails?
...one app.get (a thread error ensues). Is there a way I can flush the system and execute more gets?
– JellicleCat
May 22 '12 at 17:53
2
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What are bitwise shift (bit-shift) operators and how do they work?
I've been attempting to learn C in my spare time, and other languages (C#, Java, etc.) have the same concept (and often the same operators) ...
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Can I list-initialize a vector of move-only type?
...gspot.com/2013/09/…). The idea is to determine lvalue/rvalue at run-time and then call move or copy-construction. in<T> will detect rvalue/lvalue even though the standard interface provided by initializer_list is const reference.
– Sumant
Sep 24 '13 at ...
Rails 3.1: Engine vs. Mountable App
Can someone help me understand the differences between a Rails Engine and a Mountable app? In Rails 3.1, you can create either one with the "rails new plugin ___ " command.
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Postgres - FATAL: database files are incompatible with server
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If you recently upgraded to 11 or 12 from 10.x you can run the below command to upgrade your postgres data directory retaining all data:
brew postgresql-upgrade-database
The above command is taken from the output of brew info postgres
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Extract subset of key-value pairs from Python dictionary object?
...bigdict.get(k, None) for k in ('l', 'm', 'n')}
If you're using Python 3, and you only want keys in the new dict that actually exist in the original one, you can use the fact to view objects implement some set operations:
{k: bigdict[k] for k in bigdict.keys() & {'l', 'm', 'n'}}
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Detect if a NumPy array contains at least one non-numeric value?
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This should be faster than iterating and will work regardless of shape.
numpy.isnan(myarray).any()
Edit: 30x faster:
import timeit
s = 'import numpy;a = numpy.arange(10000.).reshape((100,100));a[10,10]=numpy.nan'
ms = [
'numpy.isnan(a).any()',
'any(n...
How to convert a byte array to a hex string in Java?
I have a byte array filled with hex numbers and printing it the easy way is pretty pointless because there are many unprintable elements. What I need is the exact hexcode in the form of: 3a5f771c
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How to read all files in a folder from Java?
... concern is efficiency, is it fast enough to be used for systems with thousands of files or is there a better alternative?
– Nitin Labhishetty
Mar 10 '14 at 15:28
17
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