Tutorial by Examples: d

Consider the following C# code Expression<Func<int, int>> expression = a => a + 1; Because the C# compiler sees that the lambda expression is assigned to an Expression type rather than a delegate type it generates an expression tree roughly equivalent to this code ParameterExpres...

document.getElementById('uniqueID') will retrieve <div id="uniqueID"></div> As long as an element with the given ID exists, document.getElementById will return only that element. Otherwise, it will return null. Note: IDs must be unique. Multiple elements cannot have the...

Hashes can be freely converted to and from arrays. Converting a hash of key/value pairs into an array will produce an array containing nested arrays for pair: { :a => 1, :b => 2 }.to_a # => [[:a, 1], [:b, 2]] In the opposite direction a Hash can be created from an array of the same form...

Basics Anonymous functions are a powerful tool of the MATLAB language. They are functions that exist locally, that is: in the current workspace. However, they do not exist on the MATLAB path like a regular function would, e.g. in an m-file. That is why they are called anonymous, although they can h...

Firebase Authentication allows the users of your app to sign-in with social providers or their email+password. But what if you want to store additional information about a user, beyond what Firebase Authentication allows you to specify? Or what if you want to display a list of the users in your app...

Complete the Installation and setup part. This will create the project in Firebase console and will also install the base SDK in your Android App. Add the dependency for Firebase Realtime Database to your app-level build.gradle file: compile 'com.google.firebase:firebase-database:9.4.0' N...

<link rel="stylesheet" href="test.css" media="print"> Media specifies what style sheet should be used for what type of media. Using the print value would only display that style sheet for print pages. The value of this attribute can be any of the mediatype val...

The std::borrow::Borrow and std::borrow::BorrowMut traits are used to treat borrowed types like owned types. For types A and B, impl Borrow<B> for A indicates that a borrowed A may be used where a B is desired. For instance, std::collections::HashMap.get() uses Borrow for its get() method,...

The std::ops::Deref and std::ops::DerefMut traits are used for overloading the dereference operator, *x. For types A and B, impl Deref<Target=B> for A indicates that dereferencing a binding of &A will yield a &B and, impl DerefMut for A indicates that dereferencing a binding of...

This is a common gotcha with Laravel routes. Routes are matched in the order that they are declared. The first matching route is the one that is used. This example will work as expected: Route::get('/posts/{postId}/comments/{commentId}', 'CommentController@show'); Route::get('/posts/{postId}', 'P...

Unlike the other helpers, this one uses static class helpers to serialize and deserialize, hence it is a little bit easier than the others to use. using Newtonsoft.Json; var rawJSON = "{\"Name\":\"Fibonacci Sequence\",\"Numbers\":[0, 1, 1, 2, 3, 5, 8, 13]}...

Use the packet manager to install Microsoft.Owin.SelfHost install-packet Microsoft.Owin.SelfHost Code for a bare minimum HelloWorld web application running from a console window: namespace HelloOwin { using System; using Owin; class Program { static readonly stri...

extern crate serde; extern crate serde_json; #[macro_use] extern crate serde_derive; #[derive(Serialize)] struct Person { #[serde(rename="firstName")] first_name: String, #[serde(rename="lastName")] last_name: String, } fn main() { let person = ...

If you created an empty project, or you still don't have mvc configured in your application, you can add dependency: "Microsoft.AspNetCore.Mvc": "1.0.1" To your project.json file under "dependencies". And register MVC middleware in your Startup class: public void ...

Sometimes builds take longer than expected. There are a few environment variables you can set to better understand what's happening during the build process. METEOR_DEBUG_BUILD=1 (logs progress) METEOR_PROFILE=<n> (logs time spent) METEOR_DEBUG_SPRINGBOARD=1 (?) METEOR_DEBUG_...

The Meteor Tool will notify you when a newer release is available. To update Meteor projects to the latest release, execute the following command inside a Meteor project: meteor update In case you want to update your Meteor project to a specific Meteor release, run the following command inside ...

Three things are usually important when starting to learn to use MPI. First, you must initialize the library when you are ready to use it (you also need to finalize it when you are done). Second, you will want to know the size of your communicator (the thing you use to send messages to other process...

CGContextRef context = UIGraphicsGetCurrentContext(); CGContextSetLineWidth(context, 5.0); CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB(); CGContextMoveToPoint(context, 200, 400); CGContextAddLineToPoint(context, 100, 100); CGContextStrokePath(context); CGColorSpaceRelease(colors...

Draw To requires Core Text framework to be added in the Build Phase [NSString* textToDraw = @"Welcome to the world Of IOS"; CFStringRef stringRef = (__bridge CFStringRef)textToDraw; CFAttributedStringRef currentText = CFAttributedStringCreate(NULL, stringRef, NULL); ...

What? : A fully supported and extensible framework for building HTTP based endpoints. In the world of HTML5, mobile devices, and modern development techniques HTTP have become the default option for building rich, scalable services. The ASP.NET Web API provides an easy to use set of default options...