Tutorial by Examples: e

Consider the following component with one input myInput and an internal value called someInternalValue. Both of them are used in a component's template. import {Component, Input} from '@angular/core'; @Component({ template:` <div> <p>{{myInput}}</p> <p>{...

Python 2.x2.7 Python 2 import urllib response = urllib.urlopen('http://stackoverflow.com/documentation/') Using urllib.urlopen() will return a response object, which can be handled similar to a file. print response.code # Prints: 200 The response.code represents the http return value. 20...

trait Hello { public function sayHello() { echo 'Hello '; } } trait World { public function sayWorld() { echo 'World'; } } class MyHelloWorld { use Hello, World; public function sayExclamationMark() { echo '!'; } } $o = new My...

trait HelloWorld { public function sayHello() { echo 'Hello World!'; } } // Change visibility of sayHello class MyClass1 { use HelloWorld { sayHello as protected; } } // Alias method with changed visibility // sayHello visibility not changed class MyClass2 { u...

Any array can be quickly decomposed by assigning its elements into multiple variables. A simple example: arr = [1, 2, 3] # --- a = arr[0] b = arr[1] c = arr[2] # --- or, the same a, b, c = arr Preceding a variable with the splat operator (*) puts into it an array of all the elements that h...

Variables don't necessarily have to expand to their values - substrings can be extracted during expansion, which can be useful for extracting file extensions or parts of paths. Globbing characters keep their usual meanings, so .* refers to a literal dot, followed by any sequence of characters; it's ...

Consider this broken snippet: def foo bar = [1, 2, 3, 4].map do |x| return 0 if x.even? x end puts 'baz' bar end foo # => 0 One might expect return to yield a value for map's array of block results. So the return value of foo would be [1, 0, 3, 0]. Instead, return retu...

The following compares two files with diff using process substitution instead of creating temporary files. diff <(curl http://www.example.com/page1) <(curl http://www.example.com/page2)

This feeds a while loop with the output of a grep command: while IFS=":" read -r user _ do # "$user" holds the username in /etc/passwd done < <(grep "hello" /etc/passwd)

Problem: Some data needs to be passed to a scene loaded from a fxml. Solution Specify a controller using the fx:controller attribute and get the controller instance created during the loading process from the FXMLLoader instance used to load the fxml. Add methods for passing the data to the contr...

Problem: Some data needs to be passed to a scene loaded from a fxml. Solution Set the controller using the FXMLLoader instance used later to load the fxml. Make sure the controller contains the relevant data before loading the fxml. Note: in this case the fxml file must not contain the fx:contro...

Problem: Some data needs to be passed to a scene loaded from a fxml. Solution Specify a controller factory that is responsible for creating the controllers. Pass the data to the controller instance created by the factory. FXML <?xml version="1.0" encoding="UTF-8"?> &...

LinqPad is a great tool that allows you to learn and test features of .Net languages (C#, F# and VB.Net.) Install LinqPad Create a new Query (Ctrl + N) Under language, select "C# statements" Type the following code and hit run (F5) string hw = "Hello World&quo...

In Elm, values are declared by writing a name, an equals sign, and then the actual value: someValue = 42 Functions are also values, with the addition of taking a value or values as arguments. They are usually written as follows: double n = n * 2 Every value in Elm has a type. The types of th...

In elm-repl, type a piece of code to get its value and inferred type. Try the following to learn about the various types that exist: > 42 42 : number > 1.987 1.987 : Float > 42 / 2 21 : Float > 42 % 2 0 : Int > 'e' 'e' : Char > "e" "e" : St...

Type variables are uncapitalized names in type-signatures. Unlike their capitalized counterparts, such as Int and String, they do not represent a single type, but rather, any type. They are used to write generic functions that can operate on any type or types, and are particularly useful for writing...

Sometimes we want to give a type a more descriptive name. Let's say our app has a data type representing users: { name : String, age : Int, email : String } And our functions on users have type signatures along the lines of: prettyPrintUser : { name : String, age : Int, email : String } -> S...

Aliasing types cuts down on boilerplate and enhances readability, but it is no more type-safe than the aliased type itself is. Consider the following: type alias Email = String type alias Name = String someEmail = "[email protected]" someName = "Benedict" sendEmail ...

index.html <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Trying out ports</title> </head> <body> <div id="app"></div> <script src="elm.js"></script> ...

Python 3 allows you to define function arguments which can only be assigned by keyword, even without default values. This is done by using star * to consume additional positional parameters without setting the keyword parameters. All arguments after the * are keyword-only (i.e. non-positional) arg...