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Pattern Matching Sealed Traits

When pattern matching an object whose type is a sealed trait, Scala will check at compile-time that all cases are 'exhaustively matched': sealed trait Shape case class Square(height: Int, width: Int) extends Shape case class Circle(radius: Int) extends Shape case object Point extends Shape ...

Installation or Setup

Detailed instructions on getting ibm-bluemix set up or installed.

If statement

if condition: body The if statements checks the condition. If it evaluates to True, it executes the body of the if statement. If it evaluates to False, it skips the body. if True: print "It is true!" >> It is true! if False: print "This won't get printed.....

Else statement

if condition: body else: body The else statement will execute it's body only if preceding conditional statements all evaluate to False. if True: print "It is true!" else: print "This won't get printed.." # Output: It is true! if False: print &...

Database Files

Display all data files for all databases with size and growth info SELECT d.name AS 'Database', d.database_id, SF.fileid, SF.name AS 'LogicalFileName', CASE SF.status & 0x100000 WHEN 1048576 THEN 'Percentage' WHEN 0 THEN 'MB...

Using Join in an Update

Joins can also be used in an UPDATE statement: CREATE TABLE Users ( UserId int NOT NULL, AccountId int NOT NULL, RealName nvarchar(200) NOT NULL ) CREATE TABLE Preferences ( UserId int NOT NULL, SomeSetting bit NOT NULL ) Update the SomeSetting column of the Prefere...

Extracting values of a given type from an Array with flatMap(_:)

The things Array contains values of Any type. let things: [Any] = [1, "Hello", 2, true, false, "World", 3] We can extract values of a given type and create a new Array of that specific type. Let's say we want to extract all the Int(s) and put them into an Int Array in a safe ...

Installation or Setup

python-requests is available on PyPI, the Python Package Index, which means it can be installed through pip: pip install requests Up-to-date source code can be found on the requests GitHub repository If you wish to install it from source, you can do this by either cloning the GitHub repository:...

Basic Template

<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-widt...

Creating a Seed

Database seeds are stored in the /database/seeds directory. You can create a seed using an Artisan command. php artisan make:seed UserTableSeeder Alternatively you can create a new class which extends Illuminate\Database\Seeder. The class must a public function named run().

Inserting Data using a Seeder

You can reference models in a seeder. use DB; use App\Models\User; class UserTableSeeder extends Illuminate\Database\Seeder{ public function run(){ # Remove all existing entrie DB::table('users')->delete() ; User::create([ 'name' => 'Admin', ...

Simple data structures

Structure data types are useful way to package related data and have them behave like a single variable. Declaring a simple struct that holds two int members: struct point { int x; int y; }; x and y are called the members (or fields) of point struct. Defining and using structs: ...

Concatenate

In (standard ANSI/ISO) SQL, the operator for string concatenation is ||. This syntax is supported by all major databases except SQL Server: SELECT 'Hello' || 'World' || '!'; --returns HelloWorld! Many databases support a CONCAT function to join strings: SELECT CONCAT('Hello', 'World'); --retur...

Installation and setup

Nginx is a Web server used to serve HTTP requests over the Internet. Nginx is available on Linux, Windows and other OSes as direct download, and can also be built from source. For detailed instructions see Nginx official reference. ubuntu/debian nginx stable version is available in official repo,...

Installation or Setup

Detailed instructions on getting azureservicebus set up or installed.

Creating a Specific Date

While the Java Date class has several constructors, you'll notice that most are deprecated. The only acceptable way of creating a Date instance directly is either by using the empty constructor or passing in a long (number of milliseconds since standard base time). Neither are handy unless you're lo...

Creating an Option value and pattern match

// The Option type can either contain Some value or None. fn find(value: i32, slice: &[i32]) -> Option<usize> { for (index, &element) in slice.iter().enumerate() { if element == value { // Return a value (wrapped in Some). return Some(index);...
Rust • Option

Basic Discriminated Union Usage

Discriminated unions in F# offer a a way to define types which may hold any number of different data types. Their functionality is similar to C++ unions or VB variants, but with the additional benefit of being type safe. // define a discriminated union that can hold either a float or a string type...

Allocating Memory

Standard Allocation The C dynamic memory allocation functions are defined in the <stdlib.h> header. If one wishes to allocate memory space for an object dynamically, the following code can be used: int *p = malloc(10 * sizeof *p); if (p == NULL) { perror("malloc() failed");...

Logging fatal errors

In PHP, a fatal error is a kind of error that cannot be caught, that is, after experiencing a fatal error a program does not resume. However, to log this error or somehow handle the crash you can use register_shutdown_function to register shutdown handler. function fatalErrorHandler() { // Let...

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