Tutorial by Examples: r

Parentheses are needed to avoid ambiguity: foo 1 |> bar 2 |> baz 3 Should be written as: foo(1) |> bar(2) |> baz(3)

String.prototype.toUpperCase(): console.log('qwerty'.toUpperCase()); // 'QWERTY'

String.prototype.toLowerCase() console.log('QWERTY'.toLowerCase()); // 'qwerty'

A predefined macro is a macro that is already understood by the C pre processor without the program needing to define it. Examples include Mandatory Pre-Defined Macros __FILE__, which gives the file name of the current source file (a string literal), __LINE__ for the current line number (an int...

Detailed instructions on getting ssl set up or installed.

/// <summary> /// Returns the data for the specified ID and timestamp. /// </summary> /// <param name="id">The ID for which to get data. </param> /// <param name="time">The DateTime for which to get data. </param> /// <returns>A Data...

To generate an XML documentation file from documentation comments in the code, use the /doc option with the csc.exe C# compiler. In Visual Studio 2013/2015, In Project -> Properties -> Build -> Output, check the XML documentation file checkbox: When you build the project, an XML file wi...

If you put your commonly used aliases into an .iex.exs file at the root of your app, IEx will load them for you on startup. alias App.{User, Repo}

Say you have a <textarea> and you want to retrieve info about the number of: Characters (total) Characters (no spaces) Words Lines function wordCount( val ){ var wom = val.match(/\S+/g); return { charactersNoSpaces : val.replace(/\s+/g, '').length, characte...

php artisan route:list --method=GET --method=POST This will include all routes that accept GET and POST methods simultaneously.

Salt can be installed via : salt-bootstrap: a shell script, that can install salt (client and/or master packages) on standard Unix/Linux platform, Platform Specific binaries: available for Windows, Mac OS X and Linux, Package Management systems: available for pacman, apt-get, yum and other pack...

TreeWalker is a generator-like interface that makes recursively filtering nodes in a DOM tree easy and efficient. The following code concatenates the value of all Text nodes in the page, and prints the result. let parentNode = document.body; let treeWalker = document.createTreeWalker(parentNode, ...

Stored procedures can be created through a database management GUI (SQL Server example), or through a SQL statement as follows: -- Define a name and parameters CREATE PROCEDURE Northwind.getEmployee @LastName nvarchar(50), @FirstName nvarchar(50) AS -- Define the query to be...

Horizontally vim -o file1.txt file2.txt Vertically vim -O file1.txt file2.txt You may optionally specify the number of splits to open. The following example opens two horizontal splits and loads file3.txt in a buffer: vim -o2 file1.txt file2.txt file3.txt

You are allowed to implement custom exceptions that can be thrown just like any other exception. This makes sense when you want to make your exceptions distinguishable from other errors during runtime. In this example we will create a custom exception for clear handling of problems the application ...

In normal mode: ~ inverts the case of the character under the cursor, gu{motion} lowercases the text covered by {motion}, gU{motion} uppercases the text covered by {motion} Example (^ marks the cursor position): Lorem ipsum dolor sit amet. ^ Lorem ipSum dolor sit amet. ~ Lorem...

The UPPER function allows you to convert all lowercase letters in a string to uppercase. SELECT UPPER('My text 123!') AS result FROM dual; Output: RESULT ------------ MY TEXT 123!

Before to launch you to code with Pug, you need to have some prerequisits. You will need to install: NodeJS with NPM ExpressJS (optional) After installing NodeJS, you can check in your terminal the correct installation doing: $ node -v If successful, it will print the number of Node's ve...

Summary This goal is to reorganize all of your scattered commits into more meaningful commits for easier code reviews. If there are too many layers of changes across too many files at once, it is harder to do a code review. If you can reorganize your chronologically created commits into topical com...

The History Microsoft windows is an operating system available in 137 languages, wrote in C,C++ & Assembly , can be installed on "ARM, IA-32, Itanium, x86-64, DEC Alpha, MIPS, PowerPC" platforms first release was in November 20 ,1985 as windows 1.0 with about 2 billion PC(per...