Tutorial by Examples: g

The following example shows the declaration of a property (StringProperty in this case) and demonstrates how to add a ChangeListener to it. import java.text.MessageFormat; import javafx.beans.property.SimpleStringProperty; import javafx.beans.property.StringProperty; import javafx.beans.value.Ch...

This example shows how to use a readonly wrapper property to create a property that cannot be written to. In this case cost and price can be modified, but profit will always be price - cost. import java.text.MessageFormat; import javafx.beans.property.IntegerProperty; import javafx.beans.property...

# list gem sources: gem sources -l # remove default gem source: gem sources -r https://rubygems.org/ # add other gem sources: gem sources -a https://ruby.taobao.org/

Mostly used under ng-repeat ngValue is useful when dynamically generating lists of radio buttons using ngRepeat <script> angular.module('valueExample', []) .controller('ExampleController', ['$scope', function($scope) { $scope.names = ['pizza', 'unicorns', 'robots']; ...

Overall the easiest way to work with JSON is to have a case class mapping directly to the JSON (same fields name, equivalent types, etc.). case class Person( name: String, age: Int, hobbies: Seq[String], pet: Pet ) case class Pet( name: String, `type`: String ) // these...

It is very easy to pass information between threads using the MVar a type and its accompanying functions in Control.Concurrent: newEmptyMVar :: IO (MVar a) -- creates a new MVar a newMVar :: a -> IO (MVar a) -- creates a new MVar with the given value takeMVar :: MVar a -> IO a -- retrieve...

Debugging is a very powerful way to have a closer look and fix incorrectly working (or non working) code. Run code step by step First thing you need to do during debugging is to stop the code at specific locations and then run it line by line to see whether that happens what's expected. Breakp...

In VBA, Strings can be declared with a specific length; they are automatically padded or truncated to maintain that length as declared. Public Sub TwoTypesOfStrings() Dim FixedLengthString As String * 5 ' declares a string of 5 characters Dim NormalString As String Debug.Print Fi...

The practice of replacing an object with a test double that verifies expectations, for instance asserting that a method has been called, is referred to as mocking. Lets assume we have SomeService to test. class SomeService { private $repository; public function __construct(Repository $r...

Since arrays are reference types, it is possible to have multiple variables pointing to the same array object. Dim array1() As Integer = {1, 2, 3} Dim array2() As Integer = array1 array1(0) = 4 Console.WriteLine(String.Join(", ", array2)) ' Writes "4, 2, 3"

If we want to replace only the first occurrence in a line, we use sed as usual: $ cat example aaaaabbbbb aaaaaccccc aaaaaddddd $ sed 's/a/x/' example xaaaabbbbb xaaaaccccc xaaaaddddd But what if we want to replace all occurrences? We just add the g pattern flag at the end: $ sed 's/a/x/...

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; /** * Person */ class Person { /** * @var int */ private $id; /** * @var string */ private $name; /** * @var int */ private $age; /** ...

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...

Postgresql-simple is a mid-level Haskell library for communicating with a PostgreSQL backend database. It is very simple to use and provides a type-safe API for reading/writing to a DB. Running a simple query is as easy as: {-# LANGUAGE OverloadedStrings #-} import Database.PostgreSQL.Simple ...

It is possible to define a data type with field labels. data Person = Person { age :: Int, name :: String } This definition differs from a normal record definition as it also defines *record accessors which can be used to access parts of a data type. In this example, two record accessors are de...

One of the most common obstacles using classes is finding the proper approach to handle private states. There are 4 common solutions for handling private states: Using Symbols Symbols are new primitive type introduced on in ES2015, as defined at MDN A symbol is a unique and immutable data typ...

To Copy Data from a CSV file to a table COPY <tablename> FROM '<filename with path>'; To insert into table user from a file named user_data.csv placed inside /home/user/: COPY user FROM '/home/user/user_data.csv'; To Copy data from pipe separated file to table COPY user FROM '/h...

To Copy table to standard o/p COPY <tablename> TO STDOUT (DELIMITER '|'); To export table user to Standard ouput: COPY user TO STDOUT (DELIMITER '|'); To Copy table to file COPY user FROM '/home/user/user_data' WITH DELIMITER '|'; To Copy the output of SQL statement to file COPY (sql st...

Data can be exported using copy command or by taking use of command line options of psql command. To Export csv data from table user to csv file: psql -p \<port> -U \<username> -d \<database> -A -F<delimiter> -c\<sql to execute> \> \<output filename with path&gt...