Tutorial by Examples: p

Installing Global Packages

Install a global package Globally installed packages drops modules in {prefix}/lib/node_modules, and puts executable files in {prefix}/bin, where {prefix} is usually something like /usr/local. Installing a global module means that its binaries end up in your PATH environment variable. Usually you'l...

npm • Getting started with npm

Basic unit test example

This example is a basic setup for unittesting the StringBuilder.toString() using junit. import static org.junit.Assert.assertEquals; import org.junit.Test; public class StringBuilderTest { @Test public void stringBuilderAppendShouldConcatinate() { StringBuilder stringBui...

junit • Getting started with junit

Hello World with doPost

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

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

EXPLAIN Select query

An Explain infront of a select query shows you how the query will be executed. This way you to see if the query uses an index or if you could optimize your query by adding an index. Example query: explain select * from user join data on user.test = data.fk_user; Example result: id select_type...

SQL • EXPLAIN and DESCRIBE

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

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

Request Permission to Use Location Services

Check the app's authorization status with: //Swift let status: CLAuthorizationStatus = CLLocationManager.authorizationStatus() //Objective-C CLAuthorizationStatus status = [CLLocationManager authorizationStatus]; Test the status against the follow constants: //Swift switch status { case ...

iOS • Core Location

How to define a test operation for a system

(in-package #:asdf-user) (defsystem #:foo :components ((:file "foo")) :in-order-to ((asdf:test-op (asdf:load-op :foo))) :perform (asdf:test-op (o c) (uiop:symbol-call :foo-tests 'run-tests))) (defsystem #:foo-tests :name "foo-test" :compo...

common-lisp • ASDF - Another System Definition Facility

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

Installation or Setup

Notepad++ can be installed: From the installer downloaded from the project's web site From Ninite, which would download and automatically install the latest version available: https://ninite.com/notepadplusplus/ Built from sources who are available in the GitHub Repo of this project.

notepad++ • Getting started with notepad++

Installation and Setup

Background ============ WebStorm is lightweight yet powerful Integrated Development Environment (IDE) perfectly equipped for complex client-side development and server-side development, it is cross-platform and works on Windows, Mac OS X, and Linux. WebStorm features advanced support for JavaScri...

webstorm • Getting started with webstorm

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

Session cookie parameters

Session cookies parameters are important both if you have a need to maintain session while getting from one subdomain to another or when, in contrary, you host backend app under /admin URL and want handle session separately. $config = [ // ... 'components' => [ // ... ...

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

Unwrap async values with async pipe

import { Component } from '@angular/core'; import { Observable } from 'rxjs/Observable'; import 'rxjs/add/observable/of'; @Component({ selector: 'async-stuff', template: ` <h1>Hello, {{ name | async }}</h1> Your Friends are: <ul> <li *ngFor=&quot...

Angular 2 • Pipes