Tutorial by Examples: sim

Open a text editor (like Notepad), and type the code below: Imports System.ComponentModel Imports System.Drawing Imports System.Windows.Forms Namespace SampleApp Public Class MainForm : Inherits Form Private btnHello As Button ' The form's constructor: thi...

Lexer rules define token types. Their name has to start with an uppercase letter to distinguish them from parser rules. INTEGER: [0-9]+; IDENTIFIER: [a-zA-Z_] [a-zA-Z_0-9]*; OPEN_PAREN: '('; CLOSE_PAREN: ')'; Basic syntax: SyntaxMeaningAMatch lexer rule or fragment named AA BMatch A follow...

Fabric is a Python (2.5-2.7) library and command-line tool for streamlining the use of SSH for application deployment or systems administration tasks. It lets you execute arbitrary Python functions via the command line. Install fabric via pip install fabric Create fabfile.py in your root directory...

public class IntStack { private IntStackNode head; // IntStackNode is the inner class of the class IntStack // Each instance of this inner class functions as one link in the // Overall stack that it helps to represent private static class IntStackNode { privat...

Sometimes, you want your threads to simultaneously share data. When this happens it is important to be aware of the code and lock any parts that could go wrong. A simple example of two threads counting is shown below. Here is some dangerous (incorrect) code: using System.Threading; class MainCl...

The most simple way to create a thread is by calling a selector "in the background". This means a new thread is created to execute the selector. The receiving object can be any object, not just self, but it needs to respond to the given selector. - (void)createThread { [self performS...

Ensure that you install the correct npm dependencies (babel decided to split itself into a bunch of packages, something to do with "peer dependencies"): npm install webpack webpack-node-externals babel-core babel-loader babel-preset-react babel-preset-latest --save webpack.config.js: mo...

:s/foo/bar Replace the first instance of foo with bar on the current line. :s/foo/bar/g Replace every instance of foo with bar on the current line. :%s/foo/bar/g Replace foo with bar throughout the entire file.

Macros are simple string replacements. (Strictly speaking, they work with preprocessing tokens, not arbitrary strings.) #include <stdio.h> #define SQUARE(x) x*x int main(void) { printf("%d\n", SQUARE(1+2)); return 0; } You may expect this code to print 9 (3*3), ...

var dispatch = d3.dispatch("statechange"); dispatch.on('statechange', function(e){ console.log(e) }) setTimeout(function(){dispatch.statechange('Hello, world!')}, 3000)

There are two different types of descriptors. Data descriptors are defined as objects that define both a __get__() and a __set__() method, whereas non-data descriptors only define a __get__() method. This distinction is important when considering overrides and the namespace of an instance's dictiona...

The scope of a variable in a block { ... }, begins after declaration and ends at the end of the block. If there is nested block, the inner block can hide the scope of a variable which is declared in the outer block. { int x = 100; // ^ // Scope of `x` begins here // } // ...

All variables in powershell begin with a US dollar sign ($). The simplest example of this is: $foo = "bar" This statement allocates a variable called foo with a string value of "bar".

Use try-finally to avoid leaking resources (such as memory) in case an exception occurs during execution. The procedure below saves a string in a file and prevents the TStringList from leaking. procedure SaveStringToFile(const aFilename: TFilename; const aString: string); var SL: TStringList; ...

Query: WITH generator ( value ) AS ( SELECT 1 FROM DUAL UNION ALL SELECT value + 1 FROM generator WHERE value < 10 ) SELECT value FROM generator; Output: VALUE ----- 1 2 3 4 5 6 7 8 9 10

First make utility class or use this method in class needed public class UIUtils { public static BitmapImageViewTarget getRoundedImageTarget(@NonNull final Context context, @NonNull final ImageView imageView, final float radius) { retur...

UI testing tools Two main tools that are nowadays mostly used for UI testing are Appium and Espresso. AppiumEspressoblackbox testwhite/gray box testingwhat you see is what you can testcan change inner workings of the app and prepare it for testing, e.g. save some data to database or sharedpreferen...

In this example we create a goroutine (a function running in a separate thread) that accepts a chan parameter, and simply loops, sending information into the channel each time. In the main we have a for loop and a select. The select will block processing until one of the case statements becomes tru...

The first thing we need to do it add EventBus to our module's gradle file: dependencies { ... compile 'org.greenrobot:eventbus:3.0.0' ... } Now we need to create a model for our event. It can contain anything we want to pass along. For now we'll just make an empty class. public ...

A simple query that selects all users from the #__users table with a username that matches John $db = JFactory::getDbo(); $query = $db->getQuery(true); $query->select('*'); $query->from('#__users'); $query->where('username = '. $db->q('John')); $db->setQuery($query); ...