Tutorial by Examples: io

In Racket, we use recursion very frequently. Here is an example of a function that sums all of the numbers from zero to the parameter, n. (define (sum n) (if (zero? n) 0 (+ n (sum (sub1 n))))) Note that there are many helpful convenience based functions used here, such as ...

The JavaScript coding convention is to place the starting bracket of blocks on the same line of their declaration: if (...) { } function (a, b, ...) { } Instead of in the next line: if (...) { } function (a, b, ...) { } This has been adopted to avoid semicolon insertion ...

manifest.json { "name": "Hello Page", "description": "Add 'Hello' to the current page.", "version": "1.0", "permissions": [ "activeTab" ], "background": { "scripts": [&quo...

AppBundle/Entity/Person.php <?php namespace AppBundle\Entity; use DoctrineORM\Mapping as ORM; use Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity; /** * @ORM\Entity * @ORM\Table(name="persons") * @ORM\Entity(repositoryClass="AppBundle\Entity\PersonRe...

There are two ways to define an anonymous function: the full syntax and a shorthand. Full Anonymous Function Syntax (fn [x y] (+ x y)) This expression evaluates to a function. Any syntax you can use with a function defined with defn (&, argument destructuring, etc.), you can also do with wi...

In the node JS command prompt, inside your loopback project, type the following command to create a new model. slc loopback:model If you have installed LoopBack CLI tool, you can create model with: lb model The command prompt will request informations about the model to create. In this examp...

Click Right Mouse on Database you want to migrate then -> Tasks -> Generate Scripts... Wizard will open click Next then chose objects you want to migrate and click Next again, then click Advanced scroll a bit down and in Types of data to script choose Schema and data (unless you want ...

Retrieve System DateTime VBA supports 3 built-in functions to retrieve the date and/or time from the system's clock. FunctionReturn TypeReturn ValueNowDateReturns the current date and timeDateDateReturns the date portion of the current date and timeTimeDateReturns the time portion of the current d...

These functions take a Variant that can be cast to a Date as a parameter and return an Integer representing a portion of a date or time. If the parameter can not be cast to a Date, it will result in a run-time error 13: Type mismatch. FunctionDescriptionReturned valueYear()Returns the year portion ...

DateDiff() DateDiff() returns a Long representing the number of time intervals between two specified dates. Syntax DateDiff ( interval, date1, date2 [, firstdayofweek] [, firstweekofyear] ) interval can be any of the intervals defined in the DatePart() function date1 and date2 are the two ...

CDate() CDate() converts something from any datatype to a Date datatype Sub CDateExamples() Dim sample As Date ' Converts a String representing a date and time to a Date sample = CDate("September 11, 2001 12:34") Debug.Print Format$(sample, "yyyy-mm-dd hh:nn:...

How To Install ANTLR in Eclipse (Last tested on Indigo and ANTLR IDE 2.1.2) Install Eclipse. Download ANTLR complete binaries jar that includes ANTLR v2. Extract to a temp directory. Copy the antlr-n.n folder to an appropriate permanent location, for example the same folder that Eclipse is in...

/// <summary> /// Read configuration values from app.config and convert to specified types /// </summary> public static class ConfigurationReader { /// <summary> /// Get value from AppSettings by key, convert to Type of default value or typ...

You can wrap values into actions and pipe the result of one computation into another: return :: Monad m => a -> m a (>>=) :: Monad m => m a -> (a -> m b) -> m b However, the definition of a Monad doesn’t guarantee the existence of a function of type Monad m => m a -&...

do-notation is syntactic sugar for monads. Here are the rules: do x <- mx do x <- mx y <- my is equivalent to do y <- my ... ... do let a = b let a = b in ...

CoffeeScript allows to deconstruct objects and arrays when they are fed to functions as arguments. A function that leverages deconstruction will specify in its signature all the fields that are expected within its body. When invoking such function, an object or array containing all the expected fie...

The example below will collect the Device's OS version number and the the version of the application (which is defined in each projects' properties) that is entered into Version name on Android and Version on iOS. First make an interface in your PCL project: public interface INativeHelper { /...

Any public Sub, Function, or Property inside a class module can be called by preceding the call with an object reference: Object.Procedure In a DateRange class, a Sub could be used to add a number of days to the end date: Public Sub AddDays(ByVal NoDays As Integer) mEndDate = mEndDate + No...

You can register for notifications of when the device text size is changed. Swift NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(updateFont), name: name:UIContentSizeCategoryDidChangeNotification, object: nil) Objective-C [[NSNotificationCenter defaultCenter] addObs...

$dbServer = "localhost,1234"; //Name of the server/instance, including optional port number (default is 1433) $dbName = "db001"; //Name of the database $dbUser = "user"; //Name of the user $dbPassword = "password"; //DB Password of that user $connectionI...