Tutorial by Examples

A web worker is a simple way to run scripts in background threads as the worker thread can perform tasks (including I/O tasks using xmlHttpRequest) without interfering with the user interface. Once created, a worker can send messages which can be different data types (except functions) to the JavaSc...

In Java, parent and child class both can have static methods with the same name. But in such cases implementation of static method in child is hiding parent class' implementation, it's not method overriding. For example: class StaticMethodTest { // static method and inheritance public stati...

use-fixtures allows to wrap each deftest in namespace with code that runs before and after test. It can be used for fixtures or stubbing. Fixtures are just functions that take test function and run it with other necessary steps (before/after, wrap). (ns myapp.test (require [clojure.test :refer ...

The text-transform property allows you to change the capitalization of text. Valid values are: uppercase, capitalize, lowercase, initial, inherit, and none CSS: .example1 { text-transform: uppercase; } .example2 { text-transform: capitalize; } .example3 { text-transform: lowerc...

Functions are defined with five components: The header, which includes the defn keyword, the name of the function. (defn welcome ....) An optional Docstring that explains and document what the function does. (defn welcome "Return a welcome message to the world" ...) Pa...

Scala can be used as a scripting language. To demonstrate, create HelloWorld.scala with the following content: println("Hello") Execute it with the command-line interpreter (the $ is the command line prompt): $ scala HelloWorld.scala Hello If you omit .scala (such as if you simply...

This is the easiest syntax to define a function: square(n) = n * n To call a function, use round brackets (without spaces in between): julia> square(10) 100 Functions are objects in Julia, and we can show them in the REPL as with any other objects: julia> square square (generic func...

Simple recursion Using recursion and the ternary conditional operator, we can create an alternative implementation of the built-in factorial function: myfactorial(n) = n == 0 ? 1 : n * myfactorial(n - 1) Usage: julia> myfactorial(10) 3628800 Working with trees Recursive functions are o...

We can use the :: syntax to dispatch on the type of an argument. describe(n::Integer) = "integer $n" describe(n::AbstractFloat) = "floating point $n" Usage: julia> describe(10) "integer 10" julia> describe(1.0) "floating point 1.0" Unlike m...

A long-form syntax is available for defining multi-line functions. This can be useful when we use imperative structures such as loops. The expression in tail position is returned. For instance, the below function uses a for loop to compute the factorial of some integer n: function myfactorial(n) ...

Functions are objects in Julia. Like any other objects, they can be passed as arguments to other functions. Functions that accept functions are known as higher-order functions. For instance, we can implement an equivalent of the standard library's foreach function by taking a function f as the firs...

Arrow syntax Anonymous functions can be created using the -> syntax. This is useful for passing functions to higher-order functions, such as the map function. The below function computes the square of each number in an array A. squareall(A) = map(x -> x ^ 2, A) An example of using this fu...

In Vue.js, every component instance has its own isolated scope, which means that if a parent component has a child component - the child component has its own isolated scope and the parent component has its own isolated scope. For any medium to large size app, following best practices conventions p...

Sometimes you will have a grid of subplots, and you want to have a single legend that describes all the lines for each of the subplots as in the following image. In order to do this, you will need to create a global legend for the figure instead of creating a legend at the axes level (which wil...

Deferred function calls serve a similar purpose to things like finally blocks in languages like Java: they ensure that some function will be executed when the outer function returns, regardless of if an error occurred or which return statement was hit in cases with multiple returns. This is useful f...

Menu items are a great way of adding custom actions to the editor. You can add menu items to the menu bar, have them as context-clicks on specific components, or even as context-clicks on fields in your scripts. Below is an example of how you can apply menu items. public class MenuItemsExample :...

The following design pattern is categorized as a creational pattern. An abstract factory is used to provide an interface for creating families of related objects, without specifying concrete classes and can be used to hide platform specific classes. interface Tool { void use(); } interf...

pacman is a simple package manager for R. pacman allows a user to compactly load all desired packages, installing any which are missing (and their dependencies), with a single command, p_load. pacman does not require the user to type quotation marks around a package name. Basic usage is as follows:...

Not always we have liberty to read from or write to a local system path. For example if R code streaming map-reduce must need to read and write to file connection. There can be other scenarios as well where one is going beyond local system and with advent of cloud and big data, this is becoming incr...

C++11 It's possible to write a generic function (for example min) which accepts various numerical types and arbitrary argument count by template meta-programming. This function declares a min for two arguments and recursively for more. template <typename T1, typename T2> auto min(const T1 &...