Tutorial by Examples: en

Using keyword arguments

You define a keyword argument in a method by specifying the name in the method definition: def say(message: "Hello World") puts message end say # => "Hello World" say message: "Today is Monday" # => "Today is Monday" You can define multip...

Ruby Language • Keyword Arguments

Required keyword arguments

2.1 Required keyword arguments were introduced in Ruby 2.1, as an improvement to keyword arguments. To define a keyword argument as required, simply declare the argument without a default value. def say(message:) puts message end say # => ArgumentError: missing keyword: message say ...

Ruby Language • Keyword Arguments

Using arbitrary keyword arguments with splat operator

You can define a method to accept an arbitrary number of keyword arguments using the double splat (**) operator: def say(**args) puts args end say foo: "1", bar: "2" # {:foo=>"1", :bar=>"2"} The arguments are captured in a Hash. You can manip...

Ruby Language • Keyword Arguments

Multidex by extending MultiDexApplication

This is very similar to using an Application subclass and overriding the attachBaseContext() method. However, using this method, you don't need to override attachBaseContext() as this is already done in the MultiDexApplication superclass. Extend MultiDexApplication instead of Application: package...

Android • Multidex and the Dex Method Limit

Executing commands in parallel using a "Single Program, Multiple Data" (SPMD) statement

Unlike a parallel for-loop (parfor), which takes the iterations of a loop and distributes them among multiple threads, a single program, multiple data (spmd) statement takes a series of commands and distributes them to all the threads, so that each thread performs the command and stores the results....

MATLAB Language • Multithreading

Declare dependencies for flavors

Dependencies can be added for specific product flavors in a similar fashion as build configurations. android { ... productFlavors { flavor1 { //... } flavor2 { //... } } } dependencies { flavor1Compile 'com.and...

android-gradle • Declare Dependencies

Use archivesBaseName to change the apk name

You can use the archivesBaseName to set the name of apk. For example: defaultConfig { .... project.ext.set("archivesBaseName", "MyName-" + defaultConfig.versionName); } You will obtain this output. MyName-X.X.X-release.apk

android-gradle • Configure Your Build with Gradle

Removing an element from a Map

To remove an element from a map use the .delete() method. map.delete(key); Example: const map = new Map([[1, 2], [3, 4]]); console.log(map.get(3)); // 4 map.delete(3); console.log(map.get(3)); // undefined This method returns true if the element existed and has been removed, otherwise fal...

JavaScript • Map

Getting and setting elements

Use .get(key) to get value by key and .set(key, value) to assign a value to a key. If the element with the specified key doesn't exist in the map, .get() returns undefined. .set() method returns the map object, so you can chain .set() calls. const map = new Map(); console.log(map.get(1)); // und...

JavaScript • Map

Getting the number of elements of a Map

To get the numbers of elements of a Map, use the .size property: const map = new Map([[1, 2], [3, 4]]); console.log(map.size); // 2

JavaScript • Map

Setting state Added of a single entity

EntityState.Added can be set in two fully equivalent ways: By setting the state of its entry in the context: context.Entry(entity).State = EntityState.Added; By adding it to a DbSet of the context: context.Entities.Add(entity); When calling SaveChanges, the entity will be inse...

Entity Framework • Managing entity state

event

An event allows the developer to implement a notification pattern. Simple example public class Server { // defines the event public event EventHandler DataChangeEvent; void RaiseEvent() { var ev = DataChangeEvent; if(ev != null) { ev(t...

C# Language • Keywords

Linking projects for faster debugging and development

Building project dependencies can sometimes be a tedious task. Instead of publishing a package version to NPM and installing the dependency to test the changes, use npm link. npm link creates a symlink so the latest code can be tested in a local environment. This makes testing global tools and proje...

Node.js • npm

Locating comments

To locate comments in BeautifulSoup, use the text (or string in the recent versions) argument checking the type to be Comment: from bs4 import BeautifulSoup from bs4 import Comment data = """ <html> <body> <div> <!-- desired text --&gt...

beautifulsoup • Locating elements

In-place replacement of a List element

This example is about replacing a List element while ensuring that the replacement element is at the same position as the element that is replaced. This can be done using these methods: set(int index, T type) int indexOf(T type) Consider an ArrayList containing the elements "Program sta...

Java Language • Lists

Approximate Numerics

float [(n)] real These data types are used to store floating point numbers. Since these types are intended to hold approximate numeric values only, these should not be used in cases where any rounding error is unacceptable. However, if you need to handle very large numbers, or numbers with an ...

Microsoft SQL Server • Data Types

Rendering text along an arc.

This example shows how to render text along an arc. It includes how you can add functionality to the CanvasRenderingContext2D by extending its prototype. This examples is derived from the stackoverflow answer Circular Text. Example rendering Example code The example adds 3 new text renderi...

html5-canvas • Text

Enum conversions

static_cast can convert from an integer or floating point type to an enumeration type (whether scoped or unscoped), and vice versa. It can also convert between enumeration types. The conversion from an unscoped enumeration type to an arithmetic type is an implicit conversion; it is possible, but ...

C++ • Explicit type conversions

submit() vs execute() exception handling differences

Generally execute() command is used for fire and forget calls (without need of analyzing the result) and submit() command is used for analyzing the result of Future object. We should be aware of key difference of Exception Handling mechanisms between these two commands. Exceptions from submit() ar...

Java Language • Executor, ExecutorService and Thread pools

Render a rounded polygon.

Creates a path from a set of points [{x:?,y:?},{x:?,y:?},...,{x:?,y:?}] with rounded corners of radius. If the corner angle is too small to fit the radius or the distance between corners does not allow room the corners radius is reduced to a best fit. Usage Example var triangle = [ { x: 200...

html5-canvas • Polygons