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Like slices, maps hold references to an underlying data structure. So by assigning its value to another variable, only the reference will be passed. To copy the map, it is necessary to create another map and copy each value: // Create the original map originalMap := make(map[string]int) originalM...

There are several good examples of using lambdas as a FunctionalInterface in simple scenarios. A fairly common use case that can be improved by lambdas is what is called the Execute-Around pattern. In this pattern, you have a set of standard setup/teardown code that is needed for multiple scenarios ...

Generic parameters can also be bound to more than one type using the T extends Type1 & Type2 & ... syntax. Let's say you want to create a class whose Generic type should implement both Flushable and Closeable, you can write class ExampleClass<T extends Flushable & Closeable> { }...

ISO/ANSI SQL: SELECT * FROM TableName FETCH FIRST 20 ROWS ONLY; MySQL; PostgreSQL; SQLite: SELECT * FROM TableName LIMIT 20; Oracle: SELECT Id, Col1 FROM (SELECT Id, Col1, row_number() over (order by Id) RowNumber FROM TableName) WHERE RowNumber <= 2...

DESCRIBE and EXPLAIN are synonyms. DESCRIBE on a tablename returns the definition of the columns. DESCRIBE tablename; Exmple Result: COLUMN_NAME COLUMN_TYPE IS_NULLABLE COLUMN_KEY COLUMN_DEFAULT EXTRA id int(11) NO PRI 0 ...

This example is a basic setup for unittesting the StringBuilder.toString() using junit. import static org.junit.Assert.assertEquals; import org.junit.Test; public class StringBuilderTest { @Test public void stringBuilderAppendShouldConcatinate() { StringBuilder stringBui...

Strategy: Strategy is a behavioural pattern, which allows to change the algorithm dynamically from a family of related algorithms. UML of Strategy pattern from Wikipedia : import java.util.*; /* Interface for Strategy */ interface OfferStrategy { public String getName(); public dou...

To add a method to a button, first create an action method: Objective-C -(void) someButtonAction{ NSLog(@"Button is tapped"); } Swift func someButtonAction() { print("Button is tapped") } Now to add this action method to your button, you have to wri...

Import the CoreLocation module in your classes that use CoreLocation functionality. //Swift import CoreLocation //Objective-C #import <CoreLocation/CoreLocation.h>

Session cookies parameters are important both if you have a need to maintain session while getting from one subdomain to another or when, in contrary, you host backend app under /admin URL and want handle session separately. $config = [ // ... 'components' => [ // ... ...

Element and attribute names live in namespaces that are URIs. Namespaces are bound to prefixes that are used in the actual element and attribute names, which are called QNames. This document binds a namespace to the prefix prefix and defines a default namespace, bound with the absence of prefix. &...

Given a Person struct struct Person { let name: String let birthYear: Int? } and an Array of Person(s) let persons = [ Person(name: "Walter White", birthYear: 1959), Person(name: "Jesse Pinkman", birthYear: 1984), Person(name: "Skyler White&quo...

Type synonym families are just type-level functions: they associate parameter types with result types. These come in three different varieties. Closed type-synonym families These work much like ordinary value-level Haskell functions: you specify some clauses, mapping certain types to others: {-# ...

Data families can be used to build datatypes that have different implementations based on their type arguments. Standalone data families {-# LANGUAGE TypeFamilies #-} data family List a data instance List Char = Nil | Cons Char (List Char) data instance List () = UnitList Int In the above de...

When defining a function, use {param1, param2, …} to specify named parameters: void enableFlags({bool bold, bool hidden}) { // ... } When calling a function, you can specify named parameters using paramName: value enableFlags(bold: true, hidden: false);

This program copies a file using readable and a writable stream with the pipe() function provided by the stream class // require the file system module var fs = require('fs'); /* Create readable stream to file in current directory named 'node.txt' Use utf8 encoding Read the data...

I/O in node is asynchronous, so interacting with the disk and network involves passing callbacks to functions. You might be tempted to write code that serves up a file from disk like this: var http = require('http'); var fs = require('fs'); var server = http.createServer(function (req, res) { ...

Download and install Xamarin Studio Community. Open Xamarin Studio. Click File → New → Solution. Click .NET → Console Project and choose C#. Click Next to proceed. Enter the Project Name and Browse... for a Location to Save and then click Create. The newly created project w...

Creating the JFrame Creating a window is easy. You just have to create a JFrame. JFrame frame = new JFrame(); Titling the Window You may wish to give your window a title. You can so do by passing a string when creating the JFrame, or by calling frame.setTitle(String title). JFrame frame = new...

Components have various parameters that can be set for them. They vary from component to component, so a good way to see what parameters can be set for components is to start typing componentName.set, and let your IDE's autocomplete (If you use an IDE) suggest methods. The default shortcut in many I...