Tutorial by Examples: i

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; ...

Open Script Editor. 2.12.4 With Mac OS X Leopard and earlier, and OS X Yosemite and later, Script Editor is located at /Applications/Utilities/Script Editor.app 2.12.4 Between Mac OS X Snow Leopard and OS X Mavericks inclusive, Script Editor is AppleScript Editor. /Applications/Utiliti...

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...

Consider the following Python2.x code. Save the file as example.py Python 2.x2.0 def greet(name): print "Hello, {0}!".format(name) print "What's your name?" name = raw_input() greet(name) In the above file, there are several incompatible lines. The raw_input() meth...

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...

Creates a Global Default Instance of a class. The default instance is accessed via the name of the class. Declaration VERSION 1.0 CLASS BEGIN MultiUse = -1 'True END Attribute VB_Name = "Class1" Attribute VB_GlobalNameSpace = False Attribute VB_Creatable = False Attribute VB_Pr...

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!" ...

VB_VarUserMemId (for module-scope variables) and VB_UserMemId (for procedures) attributes are used in VBA mostly for two things. Specifying the default member of a class A List class that would encapsulate a Collection would want to have an Item property, so the client code can do this: For i = 1...

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...

Once shadowing is turned on, every new drawing to the canvas will be shadowed. Turn off further shadowing by setting context.shadowColor to a transparent color. // start shadowing context.shadowColor='black'; ... render some shadowed drawings ... // turn off shadowing. context.shadowColor=...

Warning! Apply shadows sparingly! Applying shadowing is expensive and is multiplicatively expensive if you apply shadowing inside an animation loop. Instead, cache a shadowed version of your image (or other drawing): At the start of your app, create a shadowed version of your image in a secon...

The traditional use of shadowing is to give 2-dimensional drawings the illusion of 3D depth. This example shows the same "button" with and without shadowing var canvas=document.createElement("canvas"); var ctx=canvas.getContext("2d"); document.body.appendChild(can...

Canvas does not have CSS's inner-shadow. Canvas will shadow the outside of a filled shape. Canvas will shadow both inside and outside a stroked shape. But it's easy to create inner-shadows using compositing. Strokes with an inner-shadow To create strokes with an inner-shadow, use destinat...

INSERT INTO Invoices [ /* column names may go here */ ] VALUES (123, '1234abc', '2016-08-05 20:18:25.770', 321, 5, '2016-08-04'); Column names are required if the table you are inserting into contains a column with the IDENTITY attribute. INSERT INTO Invoices ([ID], [Num], [DateTime], [Tota...

To get the list of all backup operations performed on the current database instance: SELECT sdb.Name AS DatabaseName, COALESCE(CONVERT(VARCHAR(50), bus.backup_finish_date, 120),'-') AS LastBackUpDateTime FROM sys.sysdatabases sdb LEFT OUTER JOIN msdb.dbo.backupset bus ON bus.database_nam...

CREATE TABLE [dbo].[Customers] ( CustomerID INT DEFAULT (NEXT VALUE FOR [dbo].[CustomersSeq]) NOT NULL, CustomerName VARCHAR(100), );

INSERT INTO [dbo].[Customers] ([CustomerName]) VALUES ('Jerry'), ('Gorge') SELECT * FROM [dbo].[Customers] Results CustomerIDCustomerName10001Jerry10002Gorge

DELETE FROM [dbo].[Customers] WHERE CustomerName = 'Gorge'; INSERT INTO [dbo].[Customers] ([CustomerName]) VALUES ('George') SELECT * FROM [dbo].[Customers] Results CustomerIDCustomerName10001Jerry10003George

SCOPE_IDENTITY() returns the last identity value inserted into an identity column in the same scope. A scope is a module: a stored procedure, trigger, function, or batch. Therefore, two statements are in the same scope if they are in the same stored procedure, function, or batch. INSERT INTO ([col...