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Factors in R: more than an annoyance?
...of the basic data types in R is factors. In my experience factors are basically a pain and I never use them. I always convert to characters. I feel oddly like I'm missing something.
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Why does String.valueOf(null) throw a NullPointerException?
... that the most specific method is chosen.
A char[] is-an Object, but not all Object is-a char[]. Therefore, char[] is more specific than Object, and as specified by the Java language, the String.valueOf(char[]) overload is chosen in this case.
String.valueOf(char[]) expects the array to be non-nu...
Understanding the Event Loop
...nd get executed.
There's only 1 thread in the node process that will actually execute your program's JavaScript. However, within node itself, there are actually several threads handling operation of the event loop mechanism, and this includes a pool of IO threads and a handful of others. The key i...
What does iota of std::iota stand for?
...ase Greek letter iota.
In the quote above, I typed ι, U+03B9, “GREEK SMALL LETTER IOTA”, but Unicode actually has a dedicated code point for APL's iota: ⍳ is U+2373, “APL FUNCTIONAL SYMBOL IOTA”.
In response to the demands of commenters, I shall further address the etymology of “iot...
How can I efficiently select a Standard Library container in C++11?
... a member function rather than the one from <algorithm>. As for O(1) vs O(log n), it does not affect semantics; I'll remove the "efficiently" from the example and replace it with "easily".
– Matthieu M.
May 22 '12 at 12:22
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What are WSGI and CGI in plain English?
...ther WSGI or CGI I cringe. I've tried reading on it before but nothing really has stuck.
4 Answers
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When to use next() and return next() in Node.js
... return next() is to ensure that the execution stops after triggering the callback.
If you don't do it, you risk triggering the callback a second time later, which usually has devastating results. Your code is fine as it is, but I would rewrite it as:
app.get('/users/:id?', function(req, res, next...
Injecting $scope into an angular service function()
...table stuff), but is a Scope object. Many scope objects can be created (usually prototypically inheriting from a parent scope). The root of all scopes is the $rootScope and you can create a new child-scope using the $new() method of any scope (including the $rootScope).
The purpose of a Scope is t...
How is Docker different from a virtual machine?
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Docker originally used LinuX Containers (LXC), but later switched to runC (formerly known as libcontainer), which runs in the same operating system as its host. This allows it to share a lot of the host operating system resources. Also, i...
Determine if a sequence contains all elements of another sequence using Linq [duplicate]
...nt> hashSet = new HashSet<int>(superset);
bool contained = subset.All(i => hashSet.Contains(i));
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