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Rails 4: before_filter vs. before_action
In rails >4.0.0 generators creates CRUD operations with before_action not before_filter . It seems to do the same thing. So what's the difference between these two?
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How do you check if a selector matches something in jQuery? [duplicate]
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As the other commenters are suggesting the most efficient way to do it seems to be:
if ($(selector).length ) {
// Do something
}
If you absolutely must have an exists() function - which will be slower- you can do:
jQuery.fn.exists = function(){return this.length>0;}
Then in your...
How to remove all leading zeroes in a string
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why overcomplicate things? and mike it's $str += 0; as explained here: nabtron.com/kiss-code
– Nabeel Khan
Apr 16 '16 at 23:58
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Adding Only Untracked Files
One of the commands I find incredibly useful in Git is git add -u to throw everything but untracked files into the index. Is there an inverse of that? In the last few months, I've often found myself in a position where I've interactively added some updates to the index and I want to add all of the...
Label encoding across multiple columns in scikit-learn
I'm trying to use scikit-learn's LabelEncoder to encode a pandas DataFrame of string labels. As the dataframe has many (50+) columns, I want to avoid creating a LabelEncoder object for each column; I'd rather just have one big LabelEncoder objects that works across all my columns of data. ...
Recursion or Iteration?
Is there a performance hit if we use a loop instead of recursion or vice versa in algorithms where both can serve the same purpose? Eg: Check if the given string is a palindrome.
I have seen many programmers using recursion as a means to show off when a simple iteration algorithm can fit the bill.
D...
Should I size a textarea with CSS width / height or HTML cols / rows attributes?
... includes a textarea I have the following dilemma when I need to specify its dimensions:
12 Answers
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Add object to ArrayList at specified index
I think it's a fairly simple question, but I can't figure out how to do this properly.
14 Answers
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Apache Spark: The number of cores vs. the number of executors
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To hopefully make all of this a little more concrete, here’s a worked example of configuring a Spark app to use as much of the cluster as
possible: Imagine a cluster with six nodes running NodeManagers, each
equipped with 16 cores and 64GB of memory. The N...
Context switches much slower in new linux kernels
...S on our servers from Ubuntu 10.04 LTS to Ubuntu 12.04 LTS. Unfortunately, it seems that the latency to run a thread that has become runnable has significantly increased from the 2.6 kernel to the 3.2 kernel. In fact the latency numbers we are getting are hard to believe.
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