Tutorial by Examples: g

Coding style and recommendations

Content has been moved back to good 'ol Servlets wiki page

servlets • Getting started with servlets

Strategy pattern example in java with Context class

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...

Design patterns • Strategy Pattern

Attaching a Method to a Button

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...

iOS • UIButton

Convert a sparse matrix to a dense matrix using SciPy

from scipy.sparse import csr_matrix A = csr_matrix([[1,0,2],[0,3,0]]) >>>A <2x3 sparse matrix of type '<type 'numpy.int64'>' with 3 stored elements in Compressed Sparse Row format> >>> A.todense() matrix([[1, 0, 2], [0, 3, 0]]) >>&g...

scipy • Getting started with scipy

Legend Placed Outside of Plot

Sometimes it is necessary or desirable to place the legend outside the plot. The following code shows how to do it. import matplotlib.pylab as plt fig, ax = plt.subplots(1, 1, figsize=(10,6)) # make the figure with the size 10 x 6 inches fig.suptitle('Example of a Legend Being Placed Outside of...

matplotlib • Legends

Constructing Types

The type alias keyword combination gives a new name for a type, but the type keyword in isolation declares a new type. Let's examine one of the most fundamental of these types: Maybe type Maybe a = Just a | Nothing The first thing to note is that the Maybe type is declared with a type ...

Elm Language • Types, Type Variables, and Type Constructors

Sorting an Array

There are several sort functions for arrays in php: sort() Sort an array in ascending order by value. $fruits = ['Zitrone', 'Orange', 'Banane', 'Apfel']; sort($fruits); print_r($fruits); results in Array ( [0] => Apfel [1] => Banane [2] => Orange [3] => Zitr...

PHP • Manipulating an Array

OnChanges

Fired when one or more of the component or directive properties have been changed. import { Component, OnChanges, Input } from '@angular/core'; @Component({ selector: 'so-onchanges-component', templateUrl: 'onchanges-component.html', styleUrls: ['onchanges-component.'] }) class ...

Angular 2 • Lifecycle Hooks

Use Trigger to manage a "Recycle Bin" for deleted items

CREATE TRIGGER BooksDeleteTrigger ON MyBooksDB.Books AFTER DELETE AS INSERT INTO BooksRecycleBin SELECT * FROM deleted; GO

SQL • Triggers

Basic usage of Async/Await

You can start some slow process in parallel and then collect the results when they are done: Public Sub Main() Dim results = Task.WhenAll(SlowCalculation, AnotherSlowCalculation).Result For Each result In results Console.WriteLine(result) Next End Sub Async Functio...

Visual Basic .NET Language • Task-based asynchronous pattern

Using TAP with LINQ

You can create an IEnumerable of Task by passing AddressOf AsyncMethod to the LINQ Select method and then start and wait all the results with Task.WhenAll If your method has parameters matching the previous LINQ chain call, they will be automatically mapped. Public Sub Main() Dim tasks = Enum...

Visual Basic .NET Language • Task-based asynchronous pattern

In what package should I define my ASDF system?

ASDF provides the package ASDF-USER for developers to define their packages in.

common-lisp • ASDF - Another System Definition Facility

Stringer

The fmt.Stringer interface requires a single method, String() string to be satisfied. The string method defines the "native" string format for that value, and is the default representation if the value is provided to any of the fmt packages formatting or printing routines. package main ...

Go • Fmt

Copy to clipboard from textarea using execCommand("copy")

Example: <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title></title> </head> <body> <textarea id="content"></textarea> <input type="button" id="copy...

JavaScript • execCommand and contenteditable

Character class and common problems faced by beginner

1. Character Class Character class is denoted by []. Content inside a character class is treated as single character separately. e.g. suppose we use [12345] In the example above, it means match 1 or 2 or 3 or 4 or 5 . In simple words, it can be understood as or condition for single characters (...

Regular Expressions • Character classes

Moving scroll when UITextView becomes first responder

Observe the notifications UIKeyboardWillShowNotification and UIKeyboardWillHideNotification, update the scrollView content insets according to keyboard height, then scroll to the focused control. - (void)viewDidLoad { [super viewDidLoad]; // register for keyboard notifications [[...

iOS • UITextField

Submitting Ajax form

View file: <?php use yii; use yii\bootstrap\ActiveForm; use yii\helpers\Html; ?> <?php $form = ActiveForm::begin([ 'action' => ['comments/ajax-comment'], 'options' => [ 'class' => 'comment-form' ] ]); ?> <?= $form->field($model, '...

yii2 • Ajax Request

Setting a cookie

To set a cookie i.e. to create it and schedule for sending to the browser you need to create new \yii\web\Cookie class instance and add it to response cookies collection: $cookie = new Cookie([ 'name' => 'cookie_monster', 'value' => 'Me want cookie!', 'expire' => time() + 86...

yii2 • Cookies

Reading a cookie

In order to read a cookie use the following code: $value = \Yii::$app->getRequest()->getCookies()->getValue('my_cookie'); Note: this code allows read cookies that has been set using cookie component (because it signs all cookies by default). Therefore if you add/update cookie using JS c...

yii2 • Cookies

Changing CSS with JavaScript

Pure JavaScript It's possible to add, remove or change CSS property values with JavaScript through an element's style property. var el = document.getElementById("element"); el.style.opacity = 0.5; el.style.fontFamily = 'sans-serif'; Note that style properties are named in lower came...

CSS • Getting started with CSS