Tutorial by Examples: x

A complete hello world example.

Step 1 If you already have Django installed, you can skip this step. pip install Django Step 2 Create a new project django-admin startproject hello That will create a folder named hello which will contain the following files: hello/ ├── hello/ │ ├── __init__.py │ ├── settings.py │...

Django • Getting started with Django

Reading a text file using a FileSystemObject

Const ForReading = 1 Const ForWriting = 2 Const ForAppending = 8 Sub ReadTextFileExample() Dim fso As Object Set fso = CreateObject("Scripting.FileSystemObject") Dim sourceFile As Object Dim myFilePath As String Dim myFileText As String myFilePath = &...

VBA • Scripting.FileSystemObject

Creating a text file with FileSystemObject

Sub CreateTextFileExample() Dim fso As Object Set fso = CreateObject("Scripting.FileSystemObject") Dim targetFile As Object Dim myFilePath As String Dim myFileText As String myFilePath = "C:\mypath\to\myfile.txt" Set targetFile = fso.CreateT...

VBA • Scripting.FileSystemObject

Writing to an existing file with FileSystemObject

Const ForReading = 1 Const ForWriting = 2 Const ForAppending = 8 Sub WriteTextFileExample() Dim oFso Set oFso = CreateObject("Scripting.FileSystemObject") Dim oFile as Object Dim myFilePath as String Dim myFileText as String myFilePath = "C:\my...

VBA • Scripting.FileSystemObject

Conditional Expression (or "The Ternary Operator")

The ternary operator is used for inline conditional expressions. It is best used in simple, concise operations that are easily read. The order of the arguments is different from many other languages (such as C, Ruby, Java, etc.), which may lead to bugs when people unfamiliar with Python's "s...

Python Language • Conditionals

Sample XML (without namespaces)

Here is some sample XML against which example XPaths can be written: <r> <e a="1"/> <f a="2" b="1">Text 1</f> <f/> <g> <i c="2">Text 2</i> Text 3 <j>Text 4</j> </g&gt...

xpath • Getting started with xpath

Select text

For the sample XML (without namespaces): This XPath, /r/f/text() will select the text node with this string value: "Text 1" And this XPath, string(/r/f) will return the string value of f, which is also: "Text 1"

xpath • Getting started with xpath

Create a box-and-whisker plot with boxplot() {graphics}

This example use the default boxplot() function and the irisdata frame. > head(iris) Sepal.Length Sepal.Width Petal.Length Petal.Width Species 1 5.1 3.5 1.4 0.2 setosa 2 4.9 3.0 1.4 0.2 setosa 3 4.7 3.2 ...

R Language • boxplot

Guards (if expressions)

Case statements can be combined with if expressions to provide extra logic when pattern matching. def checkSign(x: Int): String = { x match { case a if a < 0 => s"$a is a negative number" case b if b > 0 => s"$b is a positive number" case c ...

Scala Language • Pattern Matching

Installation for Windows with VirtualBox and SSH support

To use Vagrant on Windows platform you need to install virtualization software and an ssh command-line tool first. This example will use freeware VirtualBox and Cygwin. Install VirtualBox Download the latest VirtualBox version from the official download page and run the downloaded file. Note that ...

vagrant • Getting started with vagrant

Text

The most basic input type and the default input if no type is specified. This input type defines a single-line text field with line-breaks automatically removed from the input value. All other characters can be entered into this. <input> elements are used within a <form> element to decla...

HTML • Input Control Elements

Using XPath

$html = '<html><body><span class="text">Hello, World!</span></body></html>'; $doc = new DOMDocument(); $doc->loadHTML($html); $xpath = new DOMXPath($doc); $span = $xpath->query("//span[@class='text']")->item(0); echo $span-&...

PHP • Parsing HTML

Querying complex JSON documents

Taking a complex JSON document in a table: CREATE TABLE mytable (data JSONB NOT NULL); CREATE INDEX mytable_idx ON mytable USING gin (data jsonb_path_ops); INSERT INTO mytable VALUES($$ { "name": "Alice", "emails": [ "[email protected]", ...

postgresql • JSON Support

Requiring multiple upper bounds ("extends A & B")

You can require a generic type to extend multiple upper bounds. Example: we want to sort a list of numbers but Number doesn't implement Comparable. public <T extends Number & Comparable<T>> void sortNumbers( List<T> n ) { Collections.sort( n ); } In this example T must...

Java Language • Generics

Change text

Swift textView.text = "Hello, world!" Objective-C: textView.text = @"Hello, world!";

iOS • UITextView

Set attributed text

// Modify some of the attributes of the attributed string. let attributedText = NSMutableAttributedString(attributedString: textView.attributedText!) // Use NSString so the result of rangeOfString is an NSRange. let text = textView.text! as NSString // Find the range of each element to modif...

iOS • UITextView

Change text alignment

Swift textView.textAlignment = .left Objective-C textView.textAlignment = NSTextAlignmentLeft;

iOS • UITextView

UITextViewDelegate methods

Responding to Editing Notifications textViewShouldBeginEditing(_:) textViewDidBeginEditing(_:) textViewShouldEndEditing(_:) textViewDidEndEditing(_:) Responding to Text Changes textView(_:shouldChangeTextIn:replacementText:) textViewDidChange(_:) Responding to URL textView(_: UITe...

iOS • UITextView

Change text color

Swift textView.textColor = UIColor.red Objective-C textView.textColor = [UIColor redColor];

iOS • UITextView

Check if key exists

Map<String, String> num = new HashMap<>(); num.put("one", "first"); if (num.containsKey("one")) { System.out.println(num.get("one")); // => first } Maps can contain null values For maps, one has to be carrefull not to confuse &quot...

Java Language • Maps