Tutorial by Examples: n

The name Smalltalk usually refers to ANSI Smalltalk or Smalltalk 80 (of which the first is based on). While most implementations are close to the standard, they vary in different aspects (usually referred to as dialects). Each implementation has it's own method of installation. Well known FOSS imp...

Care must be taken when initializing variables of type float to literal values or comparing them with literal values, because regular floating point literals like 0.1 are of type double. This may lead to surprises: #include <stdio.h> int main() { float n; n = 0.1; if (n > ...

Description This is a self-contained running example including/showcasing: minimum dependencies needed, Java Configuration, Bean declaration by annotation and Java Configuration, Dependency Injection by Constructor and by Property, and Pre/Post hooks. Dependencies These dependencies are needed in...

Once an object has an effective type, you should not attempt to modify it through a pointer of another type, unless that other type is a character type, char, signed char or unsigned char. #include <inttypes.h> #include <stdio.h> int main(void) { uint32_t a = 57; // conversion...

To do this first locate config folder in your root. Then open connections.js Locate // someMysqlServer: { // adapter: 'sails-mysql', // host: 'YOUR_MYSQL_SERVER_HOSTNAME_OR_IP_ADDRESS', // user: 'YOUR_MYSQL_USER', //optional // password: 'YOUR_MYSQL_PASSWORD', //optional /...

A problem: Canvas only remembers pixels, not shapes or images This is an image of a circular beach ball, and of course, you can't drag the ball around the image. It may surprise you that just like an image, if you draw a circle on a Canvas you cannot drag that circle around the canvas. That's be...

What is a "Shape"? You typically save your shapes by creating a JavaScript "shape" object representing each shape. var myCircle = { x:30, y:20, radius:15 }; Of course, you're not really saving shapes. Instead, you're saving the definition of how to draw the shapes. Then put...

Most Canvas drawings are either rectangular (rectangles, images, text-blocks) or circular (circles). Circles & rectangles have mathematical tests to check if the mouse is inside them. This makes testing circles and rectangles easy, quick and efficient. You can "hit-test" hundreds of c...

See this Example for a general explanation of dragging Shapes around the Canvas. This annotated example shows how to drag images around the Canvas // canvas related vars var canvas=document.createElement("canvas"); var ctx=canvas.getContext("2d"); canvas.width=378; canvas.h...

Here is an example of an IntentService that pretends to load images in the background. All you need to do to implement an IntentService is to provide a constructor that calls the super(String) constructor, and you need to implement the onHandleIntent(Intent) method. public class ImageLoaderIntentSe...

The exposition pipe operator, %$%, exposes the column names as R symbols within the left-hand side object to the right-hand side expression. This operator is handy when piping into functions that do not have a data argument (unlike, say, lm) and that don't take a data.frame and column names as arg...

Given the 3 points of a quadratic curve the following function returns the length. function quadraticBezierLength(x1,y1,x2,y2,x3,y3) var a, e, c, d, u, a1, e1, c1, d1, u1, v1x, v1y; v1x = x2 * 2; v1y = y2 * 2; d = x1 - v1x + x3; d1 = y1 - v1y + y3; e = v1x - 2 * x1; ...

Composing multiple functions into one is a functional programming common practice; composition makes a pipeline through which our data will transit and get modified simply working on the function-composition (just like snapping pieces of a track together)... you start out with some single responsi...

Python's built-in crypto functionality is currently limited to hashing. Encryption requires a third-party module like pycrypto. For example, it provides the AES algorithm which is considered state of the art for symmetric encryption. The following code will encrypt a given message using a passphrase...

c++17 C++17 introduces int std::uncaught_exceptions() (to replace the limited bool std::uncaught_exception()) to know how many exceptions are currently uncaught. That allows for a class to determine if it is destroyed during a stack unwinding or not. #include <exception> #include <strin...

VB_Name specifies the class or module name. Attribute VB_Name = "Class1" A new instance of this class would be created with Dim myClass As Class1 myClass = new Class1

In VBA, this attribute is ignored. It was not ported over from VB6. In VB6, it creates a Default Global Instance of the class (a "shortcut") so that class members can be accessed without using the class name. For example, DateTime (as in DateTime.Now) is actually part of the VBA.Conversio...

Adds a text description to a class or module member that becomes visible in the Object Explorer. Ideally, all public members of a public interface / API should have a description. Public Function GiveMeATwo() As Integer Attribute GiveMeATwo.VB_Description = "Returns a two!" ...

Transcrypt is a tool to precompile a fairly extensive subset of Python into compact, readable Javascript. It has the following characteristics: Allows for classical OO programming with multiple inheritance using pure Python syntax, parsed by CPython’s native parser Seamless integration with the ...

This code adds outwardly increasing shadows to an image to create a "sticker" version of the image. Notes: In addition to being an ImageObject, the "img" argument can also be a Canvas element. This allows you to stickerize your own custom drawings. If you draw text on the Can...