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Variables can be incremented or decremented by 1 with ++ or --, respectively. They can either precede or succeed variables and slightly vary semantically, as shown below. $i = 1; echo $i; // Prints 1 // Pre-increment operator increments $i by one, then returns $i echo ++$i; // Prints 2 // P...

Concept Use an Event to synchronize the scheduling of multiple coroutines. Put simply, an event is like the gun shot at a running race: it lets the runners off the starting blocks. Example import asyncio # event trigger function def trigger(event): print('EVENT SET') event.set() #...

ElementAt will return the item at index n. If n is not within the range of the enumerable, throws an ArgumentOutOfRangeException. int[] numbers = { 1, 2, 3, 4, 5 }; numbers.ElementAt(2); // 3 numbers.ElementAt(10); // throws ArgumentOutOfRangeException ElementAtOrDefault will return the item...

Concatenation refers to the operation of appending one sequence to another. Concat Concatenates two sequences to form one sequence. Method Syntax // Concat var numbers1 = new int[] { 1, 2, 3 }; var numbers2 = new int[] { 4, 5, 6 }; var numbers = numbers1.Concat(numbers2); // number...

Generation refers to creating a new sequence of values. DefaultIfEmpty Replaces an empty collection with a default valued singleton collection. Method Syntax // DefaultIfEmpty var nums = new int[0]; var numbers = nums.DefaultIfEmpty(); // numbers = { 0 } Query Syntax // Not appl...

Element operations return a single, specific element from a sequence. ElementAt Returns the element at a specified index in a collection. Method Syntax // ElementAt var strings = new string[] { "zero", "one", "two", "three" }; var str = strings.E...

<rect> represents rectangle, apart from aesthetic properties like stroke and fill, rectangle shall be defined by location and size. As for the location, it is determined by the x and y attributes. The location is relative to the rectangle’s parent. And if you don’t specify the x or y attribut...

<svg> element is the root element, or the canvas as we are drawing charts on it. SVG elements can be nested inside each other, and in this way, SVG shapes can be grouped together, meanwhile, all shapes nested inside an element will be positioned relative to its enclosing element. One thing...

SVG doesn’t currently support automatic line breaks or word wrapping, that’s when comes to rescue. element positions new lines of text in relation to the previous line of text. And by using dx or dy within each of these spans, we can position the word in relation to the word before it. Case: Anno...

To generate an ActiveRecord model that automagically creates the correct db migrations & boilerplate test files for your model, enter this command rails generate model NAME column_name:column_type 'NAME' is the name of the model. 'field' is the name of the column in the DB table and 'type' i...

Components in Vue are like widgets. They allow us to write reusable custom elements with desired behavior. They are nothing but objects which can contain any/all of the options that the root or any Vue instance can contain, including an HTML template to render. Components consist of: HTML marku...

When you bind a service to your application credentials become available through the VCAP_SERVICES environment variable. This environment variable contains JSON containing the credentials for all bound services. Example VCAP_SERVICES environment variable { "push-reappt": [ { ...

The command prompt comes pre-installed on all Windows NT, Windows CE, OS/2 and eComStation operating systems, and exists as cmd.exe, typically located in C:\Windows\system32\cmd.exe On Windows 7 the fastest ways to open the command prompt are: Press , type "cmd" and then press Enter....

This example is a snippet taken from the Extending Django User Profile like a Pro from django.db import models from django.contrib.auth.models import User from django.db.models.signals import post_save class UserProfile(models.Model): user = models.OneToOneField(User, related_name='user'...

Use the UseCors() extension method on the IApplicationBuilder in the Configure method to apply the CORS policy to all requests. public void ConfigureServices(IServiceCollection services) { services.AddMvc(); services.AddCors(); } public void Configure(IApplicationBuilder app) { ...

To enable a certain CORS policy for specific controllers you have to build the policy in the AddCors extension within the ConfigureServices method: services.AddCors(cors => cors.AddPolicy("AllowAll", policy => { policy.AllowAnyOrigin() .AllowAnyMethod() ...

Consider entities Customer, Purchase and PurchaseItem as follows: public class Customer { public string Id { get; set } // A unique Id that identifies customer public string Name {get; set; } } public class Purchase { public string Id { get; set } public string CustomerId...

GridViews allow commands to be sent from a GridView row. This is useful for passing row-specific information into an event handler as command arguments. To subscribe to a command event: <asp:GridView ID="GridView1" ... OnRowCommand="GridView1_RowCommand"> Buttons are t...

Let's say you have a service the same as the one defined in the "First service and host" example. To create a client, define the client configuration section in the system.serviceModel section of your client configuration file. <system.serviceModel> <services> <cli...

The @ContentView annotation can be used to further alleviate development of activities and replace the setContentView statement : @ContentView(R.layout.myactivity_layout) public class MyActivity extends RoboActivity { @InjectView(R.id.text1) TextView textView; @Override protected ...