Tutorial by Examples: r

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<div class="navbar navbar-inverse navbar-fixed-top"> <div class="container"> <div class="navbar-header"> <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".n...

<div class="navbar navbar-inverse navbar-fixed-top"> <div class="container"> <div class="navbar-header"> <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".n...

/* finds the next instance of needle in haystack zbpos: the zero-based position to begin searching from haystack: the string to search in needle: the string that must be found returns the next match of `needle` in `haystack`, or -1 if not found */ int findnext(int zbpos, const cha...

using System; using System.Web; using System.Web.Mvc; namespace Example.SDK.Filters { [AttributeUsage(AttributeTargets.Class, Inherited = false, AllowMultiple = false)] public sealed class CustomErrorHandlerFilter : HandleErrorAttribute { public override void OnExceptio...

If a covariant type appears as an output, the containing type is covariant. Producing a producer of Ts is like producing Ts. interface IReturnCovariant<out T> { IEnumerable<T> GetTs(); } If a contravariant type appears as an output, the containing type is contravariant. Produc...

With ASP.NET Core 1.0, the MVC and Web API framework have been merged into one framework called ASP.NET Core MVC. This is a good thing, since MVC and Web API share a lot of functionality, yet there always were subtle differences and code duplication. However, merging these two into framework one ...

LOOP AT itab INTO wa. ENDLOOP. FIELD-SYMBOLS <fs> LIKE LINE OF itab. LOOP AT itab ASSIGNING <fs>. ENDLOOP. LOOP AT itab ASSIGNING FIELD-SYMBOL(<fs>). ENDLOOP. LOOP AT itab REFERENCE INTO dref. ENDLOOP. LOOP AT itab TRANSPORTING NO FIELDS. ENDLOOP. Conditional L...

In Scala operators (such as +, -, *, ++, etc.) are just methods. For instance, 1 + 2 can be written as 1.+(2). These sorts of methods are called 'infix operators'. This means custom methods can be defined on your own types, reusing these operators: class Matrix(rows: Int, cols: Int, val data: Seq[...

Detailed instructions on getting WSO2 set up or installed. Almost all the WSO2 Products can be started using the wso2server.sh/bat files that can be found in the <Product_Home>/bin folder of each product. When you run the sh/bat script it will star the particular WSO2 product with default set...

The case modifier causes the Scala compiler to automatically generate common boilerplate code for the class. Implementing this code manually is tedious and a source of errors. The following case class definition: case class Person(name: String, age: Int) ... will have the following code automati...

There are several ways to format and get a string as a result. The .NET way is by using String.Format or StringBuilder.AppendFormat: open System open System.Text let hello = String.Format ("Hello {0}", "World") // return a string with "Hello World" let builder...

A topological ordering, or a topological sort, orders the vertices in a directed acyclic graph on a line, i.e. in a list, such that all directed edges go from left to right. Such an ordering cannot exist if the graph contains a directed cycle because there is no way that you can keep going right ...

Detailed instructions on getting magento2 set up or installed.

F|forbidden Similar to Deny, this flag forces the server to immediately return a 403 Forbidden status code to the requesting browser or client for the request. Example: Deny access to requests that end with exe: RewriteRule .exe$ - [F] G|gone If a requested resource was available in the past,...

Unity works with hierarchies in order to keep your project organized. You can assign objects a place in the hierarchy using the editor but you can also do this through code. Parenting You can set an object's parent with the following methods var other = GetOtherGameObject(); other.transform.Se...

CLP(FD) constraints are provided by all serious Prolog implementations. They allow us to reason about integers in a pure way. ?- X #= 1 + 2. X = 3. ?- 5 #= Y + 2. Y = 3.

emptyList = [] singletonList = [0] -- = 0 : [] listOfNums = [1, 2, 3] -- = 1 : 2 : [3] listOfStrings = ["A", "B", "C"]

Sometimes you want to destructure key under a map which might not be present in the map, but you want a default value for the destructured value. You can do that this way: (def my-map {:a 3 :b 4}) (let [{a :a b :b :keys [c d] :or {a 1 c 2}} my-map] (println ...

Destructurling works in many places, as well as in the param list of an fn: (defn my-func [[_ a b]] (+ a b)) (my-func [1 2 3]) ;= 5 (my-func (range 5)) ;= 3 Destructuring also works for the & rest construct in the param list: (defn my-func2 [& [_ a b]] (+ a b)) (my-func2 1 ...