Tutorial by Examples: ed

Using an already installed node version

To list available local versions of node through NVM: nvm ls For example, if nvm ls returns: $ nvm ls v4.3.0 v5.5.0 You can switch to v5.5.0 with: nvm use v5.5.0

Node.js • nvm - Node Version Manager

Stripping unwanted leading/trailing characters from a string

Three methods are provided that offer the ability to strip leading and trailing characters from a string: str.strip, str.rstrip and str.lstrip. All three methods have the same signature and all three return a new string object with unwanted characters removed. str.strip([chars]) str.strip acts o...

Python Language • String Methods

Feed a while loop with the output of a command

This feeds a while loop with the output of a grep command: while IFS=":" read -r user _ do # "$user" holds the username in /etc/passwd done < <(grep "hello" /etc/passwd)

Bash • Process substitution

Get started

index.html <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Trying out ports</title> </head> <body> <div id="app"></div> <script src="elm.js"></script> ...

Elm Language • Ports (JS interop)

Keyword-only and Keyword-required arguments

Python 3 allows you to define function arguments which can only be assigned by keyword, even without default values. This is done by using star * to consume additional positional parameters without setting the keyword parameters. All arguments after the * are keyword-only (i.e. non-positional) arg...

Python Language • *args and **kwargs

Queue Driver Configuration

Each of Laravel's queue drivers are configured from the config/queue.php file. A queue driver is the handler for managing how to run a queued job, identifying whether the jobs succeeded or failed, and trying the job again if configured to do so. Out of the box, Laravel supports the following queue ...

Laravel • Queues

Setting parameters for PreparedStatement

Placeholders in the query string need to be set by using the set* methods: String sql = "SELECT * FROM EMP WHERE JOB = ? AND SAL > ?"; //Create statement to make your operations PreparedStatement statement = connection.prepareStatement(sql); statement.setString(1, "MANAGER&...

jdbc • PreparedStatement

Simple Dual Port RAM

Simple Dual Port RAM with separate addresses and clocks for read/write operations. module simple_ram_dual_clock #( parameter DATA_WIDTH=8, //width of data bus parameter ADDR_WIDTH=8 //width of addresses buses )( input [DATA_WIDTH-1:0] data, //da...

verilog • Memories

Simple Expression Tree Generated by the C# Compiler

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...

.NET Framework • Expression Trees

Why save user data in the database

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...

firebase • How to use the Firebase Database to keep a list of Firebase Authentication users

Link 'media' attribute

HTML • Linking Resources

Borrow, BorrowMut and ToOwned

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,...

Rust • Conversion traits

Routes are matched in the order they are declared

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...

Laravel • Routing

Updating Meteor Projects & Installed Packages

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 ...

meteor • Getting started with meteor

Extensions and interfaces together enable DRY code and mixin-like functionality

Extension methods enable you to simplify your interface definitions by only including core required functionality in the interface itself and allowing you to define convenience methods and overloads as extension methods. Interfaces with fewer methods are easier to implement in new classes. Keeping o...

C# Language • Extension Methods

Nginx installation on Debian and Debian-based distros like Ubuntu

Run command below to install nginx. sudo apt-get install nginx By default, Nginx automatically starts when it is installed. You can access the default Nginx landing page to confirm that the software is running properly by visiting your server's domain name or public IP address in your web browse...

nginx • Getting started with nginx

Jagged Array Initialization

Note the parenthesis to distinguish between a jagged array and a multidimensional array SubArrays can be of different length Dim jaggedArray()() As Integer = { ({1, 2, 3}), ({4, 5, 6}), ({7}) } ' jaggedArray(0) is {1, 2, 3} and so jaggedArray(0)(0) is 1 ' jaggedArray(1) is {4, 5, 6} and so jagge...

Visual Basic .NET Language • Array

Web. Retrieving only specified properties of a Web site

ClientContext clientContext = new ClientContext(siteUrl); Web oWebsite = clientContext.Web; clientContext.Load( oWebsite, website => website.Title, website => website.Created); clientContext.ExecuteQuery(); Console.WriteLine("Title: {...

sharepoint • Working with Managed Client Side Object Model (CSOM)

List. Retrieving only specified properties of lists

ClientContext clientContext = new ClientContext(siteUrl); Web oWebsite = clientContext.Web; ListCollection collList = oWebsite.Lists; clientContext.Load( collList, lists => lists.Include( list => list.Title, list => list.Id)); clientContext.ExecuteQuery(...

sharepoint • Working with Managed Client Side Object Model (CSOM)

List. Storing retrieved lists in a collection

ClientContext clientContext = new ClientContext(siteUrl); Web oWebsite = clientContext.Web; ListCollection collList = oWebsite.Lists; IEnumerable<List> resultCollection = clientContext.LoadQuery( collList.Include( list=>list.Title, list=>list.Id)); clientCo...

sharepoint • Working with Managed Client Side Object Model (CSOM)