Tutorial by Examples: nd

The Assignment Operators (=, +=, -=, *=, /=, %=, <<=, >>= , >>>=, &=, |= and ^=)

The left hand operand for these operators must be a either a non-final variable or an element of an array. The right hand operand must be assignment compatible with the left hand operand. This means that either the types must be the same, or the right operand type must be convertible to the left o...

Java Language • Operators

Build and Run a Stack Project

In this example our project name is "helloworld" which was created with stack new helloworld simple First we have to build the project with stack build and then we can run it with stack exec helloworld-exe

Haskell Language • Stack

List multiplication and common references

Consider the case of creating a nested list structure by multiplying: li = [[]] * 3 print(li) # Out: [[], [], []] At first glance we would think we have a list of containing 3 different nested lists. Let's try to append 1 to the first one: li[0].append(1) print(li) # Out: [[1], [1], [1]] ...

Python Language • Common Pitfalls

What kinds of conditionals to use?

Use Conditionals via (syntax is in [brackets]): when [when:] Task: - name: run if operating system is debian command: echo "I am a Debian Computer" when: ansible_os_family == "Debian" loops [with_items:] loops [with_dicts:] Custom Facts [ wh...

ansible • Ansible: Loops and Conditionals

[When] Condition: `ansible_os_family` Lists

Common use when: ansible_os_family == "CentOS" when: ansible_os_family == "Redhat" when: ansible_os_family == "Darwin" when: ansible_os_family == "Debian" when: ansible_os_family == "Windows" All Lists based on discuss here http://comments...

ansible • Ansible: Loops and Conditionals

When Condition

Basic Usage Use the when condition to control whether a task or role runs or is skipped. This is normally used to change play behavior based on facts from the destination system. Consider this playbook: - hosts: all tasks: - include: Ubuntu.yml when: ansible_os_family == "Ubunt...

ansible • Ansible: Loops and Conditionals

Ordering and setting a limit

Ordering the results and setting a limit can easily be achieved with 2 additional lines added to the chain, like so: $db = JFactory::getDbo(); $query = $db->getQuery(true); $query->select('*') ->from('#__users') ->where('username = '. $db->q('John')) ->ord...

joomla3.0 • Database queries (select)

Adding Getters and Setters

Encapsulation is a basic concept in OOP. It is about wrapping data and code as a single unit. In this case, it is a good practice to declare the variables as private and then access them through Getters and Setters to view and/or modify them. public class Sample { private String name; privat...

Java Language • Getters and Setters

Passing and returning functions

The following function is returning another function as its result which can be later assigned to a variable and called: func jediTrainer () -> ((String, Int) -> String) { func train(name: String, times: Int) -> (String) { return "\(name) has been trained in the Force \(times)...

Swift Language • Functions

DependencyObject

Derives from DispatcherObject Key members public object GetValue(DependencyProperty dp); public void SetValue(DependencyProperty dp, object value); Summary Classes derived from DependencyObject participate in the dependency property system, which includes registering dependency properties ...

wpf • WPF Architecture

Simple Boilerplate : spinning cube and orbit controls with damping

This is the basic HTML file that can be used as a boilerplate when starting a project. This boilerplate uses orbit controls with damping (camera that can move around an object with deceleration effect) and creates a spinning cube. <!DOCTYPE html> <html> <head> <t...

three.js • Getting started with three.js

Undefined reference errors when linking

One of the most common errors in compilation happens during the linking stage. The error looks similar to this: $ gcc undefined_reference.c /tmp/ccoXhwF0.o: In function `main': undefined_reference.c:(.text+0x15): undefined reference to `foo' collect2: error: ld returned 1 exit status $ So l...

C Language • Common pitfalls

Creating parameterized commands

Any time SQL executed through an ADO connection needs to contain user input, it is considered best practice to parameterize it in order to minimize the chance of SQL injection. This method is also more readable than long concatenations and facilitates more robust and maintainable code (i.e. by using...

VBA • Working with ADO

Integer and String identity

Python uses internal caching for a range of integers to reduce unnecessary overhead from their repeated creation. In effect, this can lead to confusing behavior when comparing integer identities: >>> -8 is (-7 - 1) False >>> -3 is (-2 - 1) True and, using another example: ...

Python Language • Common Pitfalls

Use the String and Space functions to assign an n-character string

Dim stringOfSpaces As String 'Assign a string with 255 repeated spaces using Space$ stringOfSpaces = Space$(255) 'Assign a string with 255 repeated spaces using String$ stringOfSpaces = String$(255, " ")

VBA • Assigning strings with repeated characters

Insert an item into an array at a specific index

Simple item insertion can be done with Array.prototype.splice method: arr.splice(index, 0, item); More advanced variant with multiple arguments and chaining support: /* Syntax: array.insert(index, value1, value2, ..., valueN) */ Array.prototype.insert = function(index) { this.splice.a...

JavaScript • Arrays

Executing SQL statements as a command

// Uses Windows authentication. Replace the Trusted_Connection parameter with // User Id=...;Password=...; to use SQL Server authentication instead. You may // want to find the appropriate connection string for your server. string connectionString = @"Server=myServer\myInstance;Database=myDa...

.NET Framework • ADO.NET

Find the OS Type/Version

The first step is to import Platform from the 'react-native' package like so: import { Platform } from 'react-native' After you've done that, you can go ahead and access the OS type through Platform.OS allowing you to use it in conditional statements like const styles = StyleSheet.create({ h...

react-native • Platform Module

Initialize and getting started with React Native project

To initialize react-native init MyAwesomeProject To initialize with a specific version of React Native react-native init --version="0.36.0" MyAwesomeProject To Run for Android cd MyAwesomeProject react-native run-android To Run for iOS cd MyAwesomeProject react-native run-io...

react-native • Command Line Instructions

Referencing another class in documentation

The <see> tag can be used to link to another class. It contains the cref member which should contain the name of the class that is to be referenced. Visual Studio will provide Intellsense when writing this tag and such references will be processed when renaming the referenced class, too. /// ...

C# Language • XML Documentation Comments