Tutorial by Examples: ti

Installation or Setup

Detailed instructions on excel-formula(s). There are many formulas that you can choose from. They are divided up into 7 different categories and are on the FORMULAS tab in Excel. The categories are: Financial Logical Text Date & Time Lookup & Reference Math & trig More Function...

excel-formula • Getting started with excel-formula

Common Antipattern

You should not save props into state. It is considered an anti-pattern. For example: export default class MyComponent extends React.Component { constructor() { super(); this.state = { url: '' } this.onChange = this.onChange.bind(this); ...

React • State in React

Simple string operations

Because Regular Expressions can do a lot, it is tempting to use them for the simplest operations. But using a regex engine has a cost in memory and processor usage: you need to compile the expression, store the automaton in memory, initialize it and then feed it with the string to run it. And there...

Regular Expressions • When you should NOT use Regular Expressions

One-to-many relationships

UserType belongs to many Users <-> Users have one UserType One way navigation property with required public class UserType { public int UserTypeId {get; set;} } public class User { public int UserId {get; set;} public int UserTypeId {get; set;} public virtual UserType...

Entity Framework • Model Restraints

Required properties (NOT NULL)

By using the .IsRequired() method, properties can be specified as mandatory, which means that the column will have a NOT NULL constraint. using System.Data.Entity; // .. public class PersonContext : DbContext { // .. protected override void OnModelCreating(DbModelBuilder modelB...

Entity Framework • Code First - Fluent API

Sending a POST Request with arguments using NSURLSession in Objective-C

There are two common ways to encode a POST request body: URL encoding (application/x-www-form-urlencoded) and form data (multipart/form-data). Much of the code is similar, but the way you construct the body data is different. Sending a request using URL encoding Be it you have a server for your s...

iOS • NSURLSession

Introduction

A pointer is declared much like any other variable, except an asterisk (*) is placed between the type and the name of the variable to denote it is a pointer. int *pointer; /* inside a function, pointer is uninitialized and doesn't point to any valid object yet */ To declare two pointer variables...

C Language • Pointers

Raising SIGALARM with the default action

Using alarm, user can schedule SIGALARM signal to be raised after specified interval. In case user did not blocked, ignored or specified explicit signal handler for this signal, the default action for this signal will be performed on arrival. Per specification default action for SIGALARM is to termi...

POSIX • Signals

Installation

You can install Sinatra as a global gem: gem install sinatra or add it to a project's Gemfile # in Gemfile: gem 'sinatra' and run bundle install.

sinatra • Getting started with sinatra

Create child process and wait until it exits

This program demonstrates how to run another process using fork() and wait its termination using waitpid(): fork() creates an identical copy of the current process. The original process is the parent process, while the newly created one is the child process. Both processes continue exactly afte...

POSIX • Processes

Communicating with a Web Worker

Since workers run in a separate thread from the one that created them, communication needs to happen via postMessage. Note: Because of the different export prefixes, some browsers have webkitPostMessage instead of postMessage. You should override postMessage to make sure workers "work" (n...

JavaScript • Workers

Multiple non-identical definitions (the One Definition Rule)

If a class, enum, inline function, template, or member of a template has external linkage and is defined in multiple translation units, all definitions must be identical or the behavior is undefined according to the One Definition Rule (ODR). foo.h: class Foo { public: double x; private...

C++ • Undefined Behavior

Multiple Stylesheets

It's possible to load multiple stylesheets: <head> <link rel="stylesheet" type="text/css" href="general.css"> <link rel="stylesheet" type="text/css" href="specific.css"> </head> Note that later files a...

HTML • Using HTML with CSS

Android Step 1: Layout, Initialization, and Handling Server Response

The complete sample code for this application (Android + Node server) is available in the PayPal Developer Github repository. The first stage of creating the Android portion of our application is to set up a basic layout and handle responses that come back from the server that we'll set up in Node....

PayPal • Mobile Future Payments (End to End App)

Generating Java code from simple XSD file

XSD schema (schema.xsd) The following xml schema (xsd) defines a list of users with attributes name and reputation. <?xml version="1.0"?> <xs:schema version="1.0" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:ns="http://www...

Java Language • XJC

Basics of Higher Order Functions

Review Partial Application before proceeding. In Haskell, a function that can take other functions as arguments or return functions is called a higher-order function. The following are all higher-order functions: map :: (a -> b) -> [a] -> [b] filter :: (a -> Bool) -> [a] ...

Haskell Language • Higher-order functions

Creating Object and setting properties using reflection

Lets say we have a class Classy that has property Propertua public class Classy { public string Propertua {get; set;} } to set Propertua using reflection: var typeOfClassy = typeof (Classy); var classy = new Classy(); var prop = typeOfClassy.GetProperty("Propertua"); prop.Se...

.NET Framework • Reflection

Navigating to the beginning of a specific word

When editing text, a common task is to navigate to a particular word on the screen. In these examples we explore how we can navigate to the word updated. For the sake of consistency across the examples, we aim to land on the first letter of the word. Mid-screen jump M$B This approach is quick...

vim • Movement

Multiple Version Tables

For some tags it makes sense to have multiple version tables. There might be different subsets of a programming language or framework available, say for different device types as in this example. The different tables should be prefaced with a heading. This markup: ## desktop development kit ## ...

Documentation • Versions

Versions of an Example (multiple version tables)

If there are many version tables, the title of the desired one has to be included in angle brackets.  This content is for Micro Framework 4.4

Documentation • Versions