Tutorial by Examples: g

Simple check To check if constant is defined use the defined function. Note that this function doesn't care about constant's value, it only cares if the constant exists or not. Even if the value of the constant is null or false the function will still return true. <?php define("GOOD&quo...

Constants are created using the const statement or the define function. The convention is to use UPPERCASE letters for constant names. Define constant using explicit values const PI = 3.14; // float define("EARTH_IS_FLAT", false); // boolean const "UNKNOWN" = null; // null d...

Implementing IErrorHandler for WCF services is a great way to centralize error handling and logging. The implementation shown here should catch any unhandled exception that is thrown as a result of a call to one of your WCF services. Also shown in this example is how to return a custom object, and h...

ArgumentCondition This method checks to see if the argument specified is true. It also takes in the name of the argument that is logged if the condition fails. Assert.ArgumentCondition(pageIndex >= 0, "pageIndex", "Value must be greater than or equal to zero."); ArgumentN...

Checks to see if the passed Item is in Editing mode. If not, it throws an EditingNotAllowedException. Assert.IsEditing(Sitecore.Context.Item);

from django.db import models, IntegerField from django.contrib.postgres.fields import ArrayField class IceCream(models.Model): scoops = ArrayField(IntegerField() # we'll use numbers to ID the scoops , size=6) # our parlor only lets you have 6 scoops When you us...

This query returns all cones with a chocolate scoop and a vanilla scoop. VANILLA, CHOCOLATE, MINT, STRAWBERRY = 1, 2, 3, 4 # constants for flavors choco_vanilla_cones = IceCream.objects.filter(scoops__contains=[CHOCOLATE, VANILLA]) Don't forget to import the IceCream model from your models.py ...

You can nest ArrayFields by passing another ArrayField as it's base_field. from django.db import models, IntegerField from django.contrib.postgres.fields import ArrayField class SudokuBoard(models.Model): numbers = ArrayField( ArrayField( models.IntegerField(), ...

This query returns all cones with either a mint scoop or a vanilla scoop. minty_vanilla_cones = IceCream.objects.filter(scoops__contained_by=[MINT, VANILLA])

In order to define a Set of your own type you need to conform your type to Hashable struct Starship: Hashable { let name: String var hashValue: Int { return name.hashValue } } func ==(left:Starship, right: Starship) -> Bool { return left.name == right.name } Now you can cr...

Create a Loader object: var loader:Loader = new Loader(); //import Add listeners on the loader. Standard ones are complete and io/security errors loader.contentLoaderInfo.addEventListener(Event.COMPLETE, loadComplete); //when the loader is done loading, call this function loader.co...

Twilio's Node.JS API natively supports promises, allowing you to use promises when sending SMS messages (this example was taken and adapted directly from Twilio's API Docs). // Create an authenticated Twilio REST API client var twilio = require('twilio'); var client = new twilio.RestClient('ACCOU...

The browser function can be used like a breakpoint: code execution will pause at the point it is called. Then user can then inspect variable values, execute arbitrary R code and step through the code line by line. Once browser() is hit in the code the interactive interpreter will start. Any R code ...

Twilio help build apps that communicate with everyone in the world. Voice & Video, Messaging and Authentication APIs for every application. You can get an API key for free. To send a message through Twilio, your application needs to make an HTTP POST request to Twilio with the following things...

The FlagsAttribute should be used whenever the enumerable represents a collection of flags, rather than a single value. The numeric value assigned to each enum value helps when manipulating enums using bitwise operators. Example 1 : With [Flags] [Flags] enum Colors { Red=1, Blue=2, ...

In order to inspect an image, you can use the image ID or the image name, consisting of repository and tag. Say, you have the CentOS 6 base image: ➜ ~ docker images REPOSITORY TAG IMAGE ID CREATED SIZE centos centos6 cf2c3...

String.prototype.toUpperCase(): console.log('qwerty'.toUpperCase()); // 'QWERTY'

String.prototype.toLowerCase() console.log('QWERTY'.toLowerCase()); // 'qwerty'

Token pasting allows one to glue together two macro arguments. For example, front##back yields frontback. A famous example is Win32's <TCHAR.H> header. In standard C, one can write L"string" to declare a wide character string. However, Windows API allows one to convert between wide c...

To generate an XML documentation file from documentation comments in the code, use the /doc option with the csc.exe C# compiler. In Visual Studio 2013/2015, In Project -> Properties -> Build -> Output, check the XML documentation file checkbox: When you build the project, an XML file wi...