Tutorial by Examples | RIP Tutorial

Installation or Setup

Sonarqube uses database for storing its results and analysis. You can install MySQL for example and run it using mysql -u root -p and then run the following queries to set up the database tables. CREATE DATABASE sonar CHARACTER SET utf8 COLLATE utf8_general_ci; CREATE USER 'sonar' IDENTIFIED BY 's...

sonarqube • Getting started with sonarqube

[C] "Hello World" in Gtk+

#include <gtk/gtk.h> // callback function which is called when button is clicked static void on_button_clicked(GtkButton *btn, gpointer data) { // change button label when it's clicked gtk_button_set_label(btn, "Hello World"); } // callback function which is called ...

gtk3 • Getting started with gtk3

Array of literals

Formula in A1 ={"Item name","Quantity";"Apples",2;"Blueberries",5} Important: In certain countries the comma is used as a decimal separator (e.g: €1,00). If that's your case, you would need to use backslashes ( \ ) instead: (Docs) ={"Item name"\...

google-spreadsheet • Using arrays in Google Sheets

Basic interpolation

Interpolation means that Perl interpreter will substitute the values of variables for their name and some symbols (which are impossible or difficult to type in directly) for special sequences of characters (it is also known as escaping). The most important distinction is between single and double qu...

Perl Language • Interpolation in Perl

What is interpolated

Perl interpolates variable names: my $name = 'Paul'; print "Hello, $name!\n"; # Hello, Paul! my @char = ('a', 'b', 'c'); print "$char[1]\n"; # b my %map = (a => 125, b => 1080, c => 11); print "$map{a}\n"; # 125 Arrays may be interpolated as a whol...

Perl Language • Interpolation in Perl

setting up OL-3

openlayers-3 • Getting started with openlayers-3

Getting started with a simple map

<html> <head> <title>Getting started</title> <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/ol3/3.17.1/ol.css" type="text/css"> <script src="https://cdnjs.cloudflare.com/ajax/libs/ol3/3.17.1/ol...

openlayers-3 • Getting started with openlayers-3

Using a table valued parameter to insert multiple rows to a table

First, define a used defined table type to use: CREATE TYPE names as TABLE ( FirstName varchar(10), LastName varchar(10) ) GO Create the stored procedure: CREATE PROCEDURE prInsertNames ( @Names dbo.Names READONLY -- Note: You must specify the READONLY ) AS INSERT INTO d...

Microsoft SQL Server • Table Valued Parameters

Defining a basic module

Java Language • Modules

Expressing the power of 2

For expressing the power of 2 (2^n) of integers, one may use a bitshift operation that allows to explicitly specify the n. The syntax is basically: int pow2 = 1<<n; Examples: int twoExp4 = 1<<4; //2^4 int twoExp5 = 1<<5; //2^5 int twoExp6 = 1<<6; //2^6 ... int twoEx...

Java Language • Bit Manipulation

Get-Alias

To list all aliases and their functions: Get-Alias To get all aliases for specific cmdlet: PS C:\> get-alias -Definition Get-ChildItem CommandType Name Version Source ----------- ---- -...

PowerShell • Aliases

Set-Alias

This cmdlet allows you to create new alternate names for exiting cmdlets PS C:\> Set-Alias -Name proc -Value Get-Process PS C:\> proc Handles NPM(K) PM(K) WS(K) VM(M) CPU(s) Id SI ProcessName ------- ------ ----- ----- ----- ------ -- -- ----------- 2...

PowerShell • Aliases

Installing PostgreSQL on Windows

While it's good practice to use a Unix based operating system (ex. Linux or BSD) as a production server you can easily install PostgreSQL on Windows (hopefully only as a development server). Download the Windows installation binaries from EnterpriseDB: http://www.enterprisedb.com/products-services-...

postgresql • Getting started with postgresql

A Basic Importer

Assume you have a custom file you want to create an importer for. It could be an .xls file or whatever. In this case we're going to use a JSON file because it's easy but we're going to pick a custom extension to make it easy to tell which files are ours? Let's assume the format of the JSON file is ...

unity3d • Importers and (Post)Processors

Using the right-left or spiral rule to decipher C declaration

The "right-left" rule is a completely regular rule for deciphering C declarations. It can also be useful in creating them. Read the symbols as you encounter them in the declaration... * as "pointer to" - always on the left side [] as "array of" ...

C Language • Declarations

Goto statements

A goto statement transfers control to the statement with the corresponding label within the same function. Executing the goto statement must not cause any variables to come into scope that were not already in scope at the point of the goto. for example see the standard library source code: https:/...

Go • Branching

Creating a WeakMap object

WeakMap object allows you to store key/value pairs. The difference from Map is that keys must be objects and are weakly referenced. This means that if there aren't any other strong references to the key, the element in WeakMap can be removed by garbage collector. WeakMap constructor has an optional...

JavaScript • WeakMap

Getting a value associated to the key

To get a value associated to the key, use the .get() method. If there's no value associated to the key, it returns undefined. const obj1 = {}, obj2 = {}; const weakmap = new WeakMap([[obj1, 7]]); console.log(weakmap.get(obj1)); // 7 console.log(weakmap.get(obj2)); // undefined

JavaScript • WeakMap

Assigning a value to the key

To assign a value to the key, use the .set() method. It returns the WeakMap object, so you can chain .set() calls. const obj1 = {}, obj2 = {}; const weakmap = new WeakMap(); weakmap.set(obj1, 1).set(obj2, 2); console.log(weakmap.get(obj1)); // 1 console.log(weakmap.get(obj2)); // 2 ...

JavaScript • WeakMap

Checking if an element with the key exists

To check if an element with a specified key exits in a WeakMap, use the .has() method. It returns true if it exits, and otherwise false. const obj1 = {}, obj2 = {}; const weakmap = new WeakMap([[obj1, 7]]); console.log(weakmap.has(obj1)); // true console.log(weakmap.has(obj2)); // false...

JavaScript • WeakMap