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There are some cases in mixins where there can be single or multiple arguments while using it. Let's take a case of border-radius where there can be single argument like border-radius:4px; or multiple arguments like border-radius:4px 3px 2px 1px;. Traditional with Keyword Arguments mixing will be l...

The mcparallelDo package allows for the evaluation of R code asynchronously on Unix-alike (e.g. Linux and MacOSX) operating systems. The underlying philosophy of the package is aligned with the needs of exploratory data analysis rather than coding. For coding asynchrony, consider the future packag...

defaultProps allows you to set default prop values for your component. In the below example if you do not pass the name props, it will display John otherwise it will display the passed value class Example extends Component { render() { return ( <View> <Text>{this...

What is an enter selection? In D3.js, when one binds data to DOM elements, three situations are possible: The number of elements and the number of data points are the same; There are more elements than data points; There are more data points than elements; In the situation #3, all the data ...

If you are behind a proxy, you have to tell git about it: git config --global http.proxy http://my.proxy.com:portnumber If you are no more behind a proxy: git config --global --unset http.proxy

foreach varlist1 list1 ?varlist2 list2 ...? body foreach is a powerful control structure that allows looping over a list or multiple lists. set alpha [list a b c d e f] foreach {key} $alpha { puts "key: $key" } Multiple variable names may be specified. set alphaindexes [list a ...

Subclassing also Subclasses Singleton Class class Example end Example.singleton_class #=> #<Class:Example> def Example.foo :example end class SubExample < Example end SubExample.foo #=> :example SubExample.singleton_class.superclass #=> #<Class:Example> ...

Instances never contain a method they only carry data. However we can define a singleton class for any object including an instance of a class. When a message is passed to an object (method is called) Ruby first checks if a singleton class is defined for that object and if it can reply to that mess...

There are three ways to reopen a Singleton Class Using class_eval on a singleton class. Using class << block. Using def to define a method on the object's singleton class directly class Example end Example.singleton_class.class_eval do def foo :foo end end Example.fo...

By default Entity Framework maps decimal properties to decimal(18,2) columns in database tables. public class Box { public int Id { set; get; } public decimal Length { set; get; } public decimal Width { set; get; } public decimal Height { set; get; } } We can change the p...

A Semaphore is a high-level synchronizer that maintains a set of permits that can be acquired and released by threads. A Semaphore can be imagined as a counter of permits that will be decremented when a thread acquires, and incremented when a thread releases. If the amount of permits is 0 when a thr...

Attributes are global state (*). If they were implemented in JavaScript they would look something like this // pseudo code gl = { ARRAY_BUFFER: null, vertexArray: { attributes: [ { enable: ?, type: ?, size: ?, normalize: ?, stride: ?, offset: ?, buffer: ? }, { enabl...

//all attributes $collection = Mage::getModel('catalog/product') ->getCollection() ->addAttributeToSelect('*'); //specific attributes $collection = Mage::getModel('catalog/product') ->getCollection() ->addAttributeToSelect('name'); //certain attributes are special...

$productFound = ($product->getId() !== null)

To view difference between two branch git diff <branch1>..<branch2> To view difference between two branch git diff <commitId1>..<commitId2> To view diff with current branch git diff <branch/commitId> To view summary of changes git diff --stat <branch/com...

The revert command allows discarding unwanted uncommitted changes. Reverting changes to a single file. hg revert example.c Reverting all changes. This will discard all changes not just the current directory. hg revert --all hg will output which files were reverted. reverting exa...

Cross Platform Portability Runs on Windows, Mac OS X, Linux, and virtually every variant of unix. Event driven programming Trigger events based on variable read / write / unset. Trigger events when a command is entered or left. Trigger events when a I/O channel (file or network) becom...

ValueConverted To StringConverted To NumberConverted To Booleanundefinded"undefined"NaNfalsenull"null"0falsetrue"true"1false"false"0NaN"NaN"false"" empty string0false" "0true"2.4" (numeric)2.4true"test" (non nu...

class base { }; class derived: public base { }; int main() { base* p = new derived(); delete p; // The is undefined behavior! } In section [expr.delete] §5.3.5/3 the standard says that if delete is called on an object whose static type does not have a virtual destructor: if the...

In C++ methods that differs only by const qualifier can be overloaded. Sometimes there may be a need of two versions of getter that return a reference to some member. Let Foo be a class, that has two methods that perform identical operations and returns a reference to an object of type Bar: class ...