Tutorial by Examples: u

When filtering a URL filter_var() will return the filtered data, in this case the URL, or false if a valid URL cannot be found: URL: example.com var_dump(filter_var('example.com', FILTER_VALIDATE_URL)); var_dump(filter_var('example.com', FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED)); var_du...

C++11 C++11 introduces two new special member functions: the move constructor and the move assignment operator. For all the same reasons that you want to follow the Rule of Three in C++03, you usually want to follow the Rule of Five in C++11: If a class requires ONE of five special member functions...

C++11 We can combine the principles of the Rule of Five and RAII to get a much leaner interface: the Rule of Zero: any resource that needs to be managed should be in its own type. That type would have to follow the Rule of Five, but all users of that resource do not need to write any of the five sp...

Single node Installation Pre-install NodeJS, Python and Java Select your installation document based on your platform http://docs.datastax.com/en/cassandra/3.x/cassandra/install/installTOC.html Download Cassandra binaries from http://cassandra.apache.org/download/ Untar the downloaded file to ...

Update the entire object: db.people.update({name: 'Tom'}, {age: 29, name: 'Tom'}) // New in MongoDB 3.2 db.people.updateOne({name: 'Tom'},{age: 29, name: 'Tom'}) //Will replace only first matching document. db.people.updateMany({name: 'Tom'},{age: 29, name: 'Tom'}) //Will replace all matchin...

Generators are useful when you need to generate a large collection to later iterate over. They're a simpler alternative to creating a class that implements an Iterator, which is often overkill. For example, consider the below function. function randomNumbers(int $length) { $array = []; ...

Our randomNumbers() function can be re-written to use a generator. <?php function randomNumbers(int $length) { for ($i = 0; $i < $length; $i++) { // yield tells the PHP interpreter that this value // should be the one used in the current iteration. yield mt...

The AppCompat Support Library defines several useful styles for Buttons, each of which extend a base Widget.AppCompat.Button style that is applied to all buttons by default if you are using an AppCompat theme. This style helps ensure that all buttons look the same by default following the Material D...

Filter code: angular.module('myModule', []).filter('multiplier', function() { return function(number, multiplier) { if (!angular.isNumber(number)) { throw new Error(number + " is not a number!"); } if (!multiplier) { multiplier = 2; } return numbe...

404 responses are returned when a resource is not found on the server, in Symfony this status can be created by throwing a NotFoundHttpException exception. To avoid an extra use statement inside a controller use the createNotFoundException() provided by the Controller class <?php namespace Bu...

To assert that a value is either true or false,: Assert.IsFalse(Settings.DoBadThings, "Bad things should not happen, disable DoBadThings."); Assert.IsTrue(magicNumber =< 42, "The magic number is greater than 42!"); You can also pass formatting parameters for the exception...

ResultNotNull() checks to see if the object passed in is not null. If the object and message are not null it will then simply return the object that was passed in, otherwise it will throw InvalidOperationException. return Assert.ResultNotNull(this.Database.GetItem(this.ItemRootId), string.Concat(&q...

This checks to see if the given object is null, and then throws RequiredObjectIsNullException if it is. Assert.Required(parameter, "parameter is required.");

IsNotNull This is a very simple and popular method to use to check if an item is not null. It simply checks the object that is passed in to see if it is null. Assert.IsNotNull(database, type, "Name: {0}", item); IsNotNullOrEmpty This is the same as IsNotNull above, but works on strin...

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);

CanRunApplication To check to see if the user has permission to run the given application. If not, AccessDeniedException is thrown. Assert.CanRunApplication("WebEdit"); HasAccess HasAccess will check if the given parameter is true, otherwise an AccessDeniedException will be thrown. ...

When writing a class with generics in java, it is possible to ensure that the type parameter is an enum. Since all enums extend the Enum class, the following syntax may be used. public class Holder<T extends Enum<T>> { public final T value; public Holder(T init) { t...

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 ...