Difference between array, arraylist, List, Hashtable, Dictionary and SortedList in c#

-
Basic difference is that arrays are of fixed size. Whereas an ArrayList implements the list data structure and can dynamically grow. While arrays would be more performance that a list, a list would be far more flexible since you don't need to know the required size initially. Array - represents an old-school memory array - kind of like a alias for a normal type[] array. Can enumerate. Can't grow automatically. I would assume very fast insertion, retrieve and speed. ArrayList - automatically growing array. Adds more overhead. Can enum., probably slower than a normal array but still pretty fast. These are used a lot in .NET List - one of my favorites - can be used with generics, so you can have a strongly typed array, e.g. List . Other than that, acts very much like ArrayList. Hashtable - plain old hashtable. O(1) to O(n) worst case. Can enumerate the value and keys properties, and do key/val pairs. Dictionary - same as above only strongly typed via generics, such a...
Post a Comment

All about AngularJs framework

-
"AngularJS is a JavaScript framework which simplifies binding JavaScript objects with HTML UI elements."

Let us try to understand the above definition with simple sample code.

Below is a simple "Customer" function with "CustomerName" property. We have also created an object called as "Cust" which is of "Customer" class type.


function Customer()
{
this.CustomerName = "AngularInterview";
}
var Cust = new Customer();

Now let us say the above customer object we want to bind to a HTML text box called as "TxtCustomerName". In other words when we change something in the HTML text box the customer object should get updated and when something is changed internally in the customer object the UI should get updated.


<input type=text id="TxtCustomerName" onchange="UitoObject()"/>

So in order to achieve this communication between UI to object developers end up writing functions as shown below. "UitoObject" function takes data from UI and sets it to the object while the other function "ObjecttoUI" takes data from the object and sets it to UI.


function UitoObject()
{
Cust.CustomerName = $("#TxtCustomerName").val();
}
function ObjecttoUi()
{
$("#TxtCustomerName").val(Cust.CustomerName);
}

So if we analyze the above code visually it looks something as shown below. Your both functions are nothing but binding code logic which transfers data from UI to object and vice versa.


Now the same above code can be written in Angular as shown below. The javascript class is attached to a HTML parent div tag using "ng-controller" directive and the properties are binded directly to the text box using "ng-model" declarative.

So now whatever you type in the textbox updates the "Customer" object and when the "Customer" object gets updated it also updates the UI.


<div ng-controller="Customer">
<input type=text id="txtCustomerName"  ng-model="CustomerName"/>
</div>

In short if you now analyze the above code visually you end up with something as shown in the below figure.You have the VIEW which is in HTML, your MODEL objects which are javascript functions and the binding code in Angular.



Now that binding code have different vocabularies.
•Some developers called it "ViewModel" because it connects the "Model" and the "View" .
•Some call it "Presenter" because this logic is nothing but presentation logic.
•Some term it has "Controller" because it controls how the view and the model will communicate.

To avoid this vocabulary confusion Angular team has termed this code as "Whatever". It's that "Whatever" code which binds the UI and the Model. That's why you will hear lot of developers saying Angular implements "MVW" architecture.

Comments

Post a Comment

Popular posts from this blog

C# Interview Questions on Inheritance

-
What are the 4 pillars of any object oriented programming language? 1. Abstraction 2. Inheritance 3. Encapsulation 4. Polymorphism Do structs support inheritance? No, structs do not support inheritance, but they can implement interfaces. What is the main advantage of using inheritance? Code reuse Is the following code legal? class ChildClass : ParentClassA, ParentClassB { } No, a child class can have only one base class. You cannot specify 2 base classes at the same time. C# supports single class inheritance only. Therefore, you can specify only one base class to inherit from. However, it does allow multiple interface inheritance. What will be the output of the following code? using System; public class BaseClass { public BaseClass() { Console.WriteLine("I am a base class"); } } public class ChildClass : BaseClass { public ChildClass() { Console.WriteLine("I am a child class"); } static void Main() { ChildClass CC = new ChildClass(); } } Output: I am a base clas...
Read more

C# Interview Questions on value types and reference types

-
What are the 2 types of data types available in C#? 1. Value Types 2. Reference Types If you define a user defined data type by using the struct keyword, Is it a a value type or reference type? Value Type If you define a user defined data type by using the class keyword, Is it a a value type or reference type? Reference type Are Value types sealed? Yes, Value types are sealed. What is the base class from which all value types are derived? System.ValueType Give examples for value types? Enum Struct Give examples for reference types? Class Delegate Array Interface What are the differences between value types and reference types? 1. Value types are stored on the stack where as reference types are stored on the managed heap. 2. Value type variables directly contain their values where as reference variables holds only a reference to the location of the object that is created on the managed heap. 3. There is no heap allocation or garbage collection overhead for value-type variables. As ...
Read more

Why to use UpdatePanel control in AJAX ASP.NET?

-
AJAX is a client side technology and it supports asynchronous communication between client and server. If the part of page need to be refreshed, then we can use this Update panel control, which uses AJAX request and does not harm the other part of the page. Using Update Panel improves the user experience of the page since it does not refresh the whole page.
Read more