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How to learn R as a programming language [closed]
...ion is prompted by lack of understanding of such functions as parse, eval, etc. which may not find frequent use by an R user with a 'statistics' persuasion.
...
How to check if array is empty or does not exist? [duplicate]
...arios, such as null values, other types of objects with a length property, etc. It is also not very idiomatic JavaScript.
The foolproof approach
Taking some inspiration from the comments, below is what I currently consider to be the foolproof way to check whether an array is empty or does not exist....
How do JavaScript closures work?
...s created and a completely new variable x, and a new set of functions (log etc.) are created, that close over this new variable.
function createObject() {
let x = 42;
return {
log() { console.log(x) },
increment() { x++ },
update(value) { x = value }
}
}
const o = createObject...
How do I clear the terminal screen in Haskell?
...s functions for clearing the screen, displaying colors, moving the cursor, etc. Using it to clear the screen is easy: (this is with GHCI) import System.Console.ANSIclearScreen
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How to enable local network users to access my WAMP sites?
...s
Inside alias folder you will see some files
like phpmyadmin,phpsysinfo,etc...
open each file, and you can see inside file some commented instruction are give to access from outside ,like
to give access to phpmyadmin from outside
replace the lines
Require local
by
Require all granted...
Java inner class and static nested class
...class A can contain class B which contains class C which contains class D, etc. However, more than one level of class nesting is rare, as it is generally bad design.
There are three reasons you might create a nested class:
organization: sometimes it seems most sensible to sort a class into the na...
Android Fragments. Retaining an AsyncTask during screen rotation or configuration change
...
@jakk The lifecycle methods for Activitys, Fragments, etc. are invoked sequentially by the main GUI thread's message queue, so even if the task finished concurrently in the background before these lifecycle methods completed (or even invoked), the onPostExecute method would stil...
What is the most effective way for float and double comparison?
...types.h doesn't compile on Windows, we cannot use
// uint32, uint64, and etc here.
typedef int Int;
typedef unsigned int UInt;
};
// The specialization for size 8.
template <>
class TypeWithSize<8> {
public:
#if GTEST_OS_WINDOWS
typedef __int64 Int;
typedef unsigned __int64 U...
Standard Android menu icons, for example refresh [closed]
...download a lot of sources editable with Fireworks, Illustrator, Photoshop, etc...
And there's also fonts and icon packs.
Here is a stencil example.
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How to explain callbacks in plain english? How are they different from calling one function from ano
...a.results ? jsondata.results.length : 0;
$('#counter_messages').text(['Fetched', count, 'new items'].join(' '));
$('#results_messages').html(jsondata.results || '(no new messages)');
}
With Callback:
Here is an example with a callback, using jQuery's getJSON:
function processDataCB(jsondat...