Assume how the Facebook application will store the millions of customer's record in real-time:

facebook = {
'jose': {
'name': 'jose', 'age': 33,
'hobby': ['cricket', 'python'], # cricket,football
'mobile': 1111111111, 'email': 'joset@gmail.com',
'contacts':[6666666666,3333333333,4444444444],
'pages': {
'python': {'sudha', 'priyanka'},
'BusinessMantra': {'sudha', 'oviya'}
}
},
'sudha': {
'name': 'sudha', 'age': 32, 'hobby': ['Khabadi', 'Movies', chess'],
'mobile': 2222222222, 'email': 'sudha.ram@gmail.com',
'contacts':[5555555555],
'pages':{
'python':{'sudha', 'lok'},
'furnitures': {'chris', 'priyanka'}
}
},
'lok': {
'name': 'lok', 'age': 26, 'hobby': ['python','football'],
'mobile': 3333333333, 'email': 'lok123@gmail.com',
'contacts':[3333333333,7777777777],
'pages':{
'python':{'chris', 'priyanka', 'jose'}
}
},
'priyanka': {
'name': 'priyanka', 'age': 26, 'hobby': 'football',
'mobile': 4444444444, 'email': 'pravi@gmail.com',
'contacts':[5555555555,3333333333,4444444444],
'pages':{'python':{'chris', 'jose'}}
},
'chris': {
'name': 'chris', 'age': 35, 'hobby': 'football',
'mobile': 5555555555, 'email': 'christopher.e@gmail.com',
'contacts':[6666666666,3333333333,4444444444]}
}

Assignment I(Store data):

1. You have to allow fb-customer to enter multiple hobbies with comma separator(,) and you have to store them as a list in db.
   Ex: 'jose': {'name': 'jose', 'age': '33', 'hobby': ['cricket', 'python']
2. Sync Contacts: Basically facebook(Messenger) will sync all your contacts to it's database. Here, the user will enter all his contacts(mobile numbers) with comma separator, that you have to store as a list like below,
   input: '6666666666,3333333333,4444444444' and store it in db like the below,
   'contacts':[6666666666,3333333333,4444444444]
3. Validate the input of mobile number as 10-digit(Ex:9876543210), ask repeatedly if they enter invalid input.
   Ex: Enter you mobile number:88 (if the user entered non 10-digit number, ask them correct mobile number until the valid input)
   Enter valid mobile number: 9876543210
4. Validate the Email-id with the format of Gmail account
5. Get the Age and Mobile number as integer input
6. A customer can run any number of pages, add an item as the above sample into their database with the pages and it's followers(set datatype)

Assignment II(Read operation):

1. Find the person who has the hobby same as I am looking: List all the customer who has cricket as hobby
2. Find the Target group for digital advt: A customer approaching FB to promote his page. How will they find the intended audience for the page-suggestion?
   Ex: I wants to promote my 'Python Development&Automation' page, then how will you pick the right person for my page among the millions of user-profile exist in the fb db.
3. Suggest Friend: We usually get friend suggestion from facebook analytics. Have you ever wonder how does it work..? Let's simulate this.
   As you know the pattern of stored data(facebook), you can classify the category like(same School/Company/Community/Birthplace/CurrentLocation/Contacts)
4. When the customer posting a status on their page, we have to let this know to all the followers
   Ex: sudha wants to post the status in his ‘furnitures’ page, notify this to all it's followers

I want to join the coaching for net in education subject at Kanpur (Gurdev palace ). Please suggest me best coaching for net. 

- Basically , a Method is a piece of code used for the re-usability purpose. 

- Method is of 2 types Function and Procedure

- Function is a method which returns a value to the calling place

Procedure is a method which returns nothing to the calling place.

Procedure syntax:

<procedurename>(<params>[optional])

{

    //code

}

Procedure samples:

Display()

{

     Console.WriteLine("Procedure returns no value");

}

Add(int a, int b)

{

     Console.WriteLine("Sum : "+(a+b));

}

Hence, a function always returns a value or void to the calling place and a procedure returns nothing.

C# do not support Procedure. So functions in C# should be defined with the return type.

Control to validate an error message. Are common feature in all the controls.

Various validators are requiredfeild validator ,compare validator ,regular expression validator,custom validator,range validator  and validation summary.

1. Required field validator asks for the missing field in server side controls like textboxes dropdowlistot list box or checkboxlist and tells to populate in the form of error message.

2. Compare validator asks for two textboxes or familiar controls to have the exact match of the data types ore expressions.

3. Regular expression validator asks for correct format of email passwords and phone numbers or website address.

4. The custom validator does the same what regular expression validator does additionally it can customize its own features of validation by language coding means.

5.Validation summary. Display list of error messages in the form of bullet list on the top of the registration page etc.

6. Range validator checks whether the data types entered is falling in the correct ranges. Example values between two integer or dates or strings or float currencies etc..

• ArgumentException, ArgumentNullException, and ArgumentOutOfRangeException.
• NullReferenceException, IndexOutOfRangeException, SQL exceptions
• Stack Overflow Exception, Invalid Castexception

ArgumentException occurs due to the appearance of invalid argument types

argument null exception is due to null argument appearances. and out of range is when argument is defined which exceeds within its own bound levels.

null reference exception is when referencing an object you come across null character.

 IndexOutOfRangeException is when the index is defined beyond the actual bound levels. like in arrays. carrying integers of other characters.

sql exception is when mismatch happens between the number of rows or columns or irrelevant data types happens when client-side access the server side. in the database.

InvalidCastexception happens when the wrong type of casting happens between to data types for example between string and integer.

StackOverflowException happens when stacks try to acquire values beyond its own bound levels preassigned.

foreach is a looping statement :

• repeats a group of statements for each element in an array or an object collection. (or)
• used to iterate through the collection/ an array to get the required information.

Advantages:

• Easy implementation.
• Least possibility of errors. [ especially when working with index based values, like in arrays. ]

Syntax:

foreach(<datatype of collection / array> <variablename> <in> <collection/array>)
{

code....

}

Example:

foreach(string courseName in coursesList)
{

code....

}

• here, coursesList is a string collection
• string courseName is called as the "loop variable" which represents the element from the collection in each iteration.
• in is the pre-defined keyword

Working style of foreach loop:

• data type of loop variable must and should be the same as the data type of the array/collection that has to be referred.
• At the time of execution, first the foreach loop goes to the array/collection, counts the number of elements & repeats the loop that many times automatically.
• At each iteration array/collection location value will be copied into loop variable.

Example 1: In the below example, we'll see how to iterate a group of int type array elements using foreach loop.

Example 2: In the below example, we'll see how to iterate a group of values in a collection.

NOTE : in .NET we've different types of collections. For example we took "List" a generic collection

Session Objectives:

Discuss the following:

Drawbacks of traditional programming

Need for Object: Oriented approach

Object: Oriented techniques

Discuss Object: Oriented Concepts

• Objects.
• Classes.
• Abstraction.
• Inheritance.
• Encapsulation.
• Polymorphism.

Need for OOP:

• Languages like C use the traditional programming approach for application development.
• In this approach, we divide the application into several tasks and write code for all tasks.
• Therefore, the focus in this approach is on the tasks and not on the objects.
• The traditional programming approach was not able to handle the increasing demand of software applications

The drawbacks of Traditional Programming approach are:

• Unmanageable Programs.
• Code Reusability not Optimum.
• Problems in Modification of Data.
• Difficulty in Implementation.

Benefits of Object Oriented Programming approach are:

• OOP offers better implementation.
• OOP offers better data security.
• OOP offers better code reusability.
• OOP offers more flexibility.
• OOP offers better manageable programs.

Objects:

• An object represents an entity in the real world.
• An object is simply something that is relevant to a particular application.
• An object is a concept or a thing, with defined boundaries, that is relevant to the problem being dealt with.

Classes:

• A class is a mould or a template of an object.
• A class is what defines all the data members and the methods that an object should have.
• The class defines the characteristics that the object will possess;it could also be referred to as a blueprint of the object.
• Each object is said to be an instance of the class.
• A class can contain any of the following as its members Properties / Fields,Methods,Constructors & Destructors
• Properties: A characteristic required of an object when represented in a class is called a property or a field.
• Method: A method is similar to a function, routine or a procedure; here it is associated to a class.
• Constructor / Destructor: These are special types of methods that execute when an object is initialized or destroyed respectively.

Abstraction:

• Data abstraction enhances security as use of data is restricted to certain functions only.
• Abstraction is more used where you want only a certain number of functions/methods are accessing data

Inheritance:

• We can incorporate the functionality of existing classes into any other class just by inheriting the new class from the existing class.
• The existing class is called the BASE class and the newly created class is called the DERIVED class.

Data Encapsulation:

• Grouping of data and methods into a single entity is known as Data Encapsulation

Polymorphism:

• Object: Oriented languages try to make existing code easily modifiable without changing the code much.
• Polymorphism allows functions to take more than one form.
• Polymorphism enables the same method to behave differently on different classes.

What you will learn in Pro-Developer Program:

i. Introduction:

Object initializers and Collection initializers are part of C# 3.0.These two concepts add a flexibility, readability, and maintainability in C#. As we are C# developers, we should know how and in which situations we can use these two concepts and inprove our programming logic. Before going deep, dive into object and collection initializers. We will check what are these Syntactic Sugars.

ii. Syntactic sugar in programming:

Syntactic sugar, or syntax sugar, is considered as a "shortcut" provided by the language, which reduces the amount of code that must be written in a particular situation.

Syntactic sugar is syntax within a programming language that is designed to make things easier to read or to express. It makes the language "sweeter" for human use: things can be expressed more clearly, more concisely, or in an alternative style that some may prefer.

The main benifits of using syntatic sugar in programming are:

1. Avoid lot of keystrokes,The efficiency of software programs is sometimes measured by the number of keystrokes it requires to write a specific function.

2. Easy to readable and maintainable.

3. Time saving approach.

Let's see an example of  how we can use syntactic sugar in our program. Let's consider an example of normal IF-ELSE conditional statement:

class Program
{
static void Main(string[] args)
{
int x = 20, y = 10;
if (x>y)
{
Console.WriteLine(x);

}
else
{
Console.WriteLine(y);

}
Console.ReadLine();

}

Now, let's use Ternary operators and see how much key strokes we can prevent using Ternary operator.

class Program
{
static void Main(string[] args)
{
int x = 20, y = 10;
var result = x > y ? x : y;
Console.WriteLine(result);
Console.ReadLine();

}

So, in this way, we can say that by using ternary operator, we can achive syntactic sugar in our programming. Now, let's come to our main topic about Object Initialization and Collection Initialization.

So in programming, initialization is the assignment of an initial value for a data object or variable.

iii. Object Initializers:

Before going toward object initializers, let us see how we are initialising a object in C# 2.0:

public class Employee
{
public string Name { get; set; }
public int Id { get; set; }
public string Department { get; set; }
public int salary { get; set; }
}
class Program
{
static void Main(string[] args)
{
Employee emp=new Employee();
emp.Name = "Kumar";
emp.Department = "IT";
emp.Id = 101;
emp.salary = 80000;
Console.ReadLine();

}
}

Let's see how we can do that using object initializer in C# 3.0.

Write the same program using Object Initializer:

class Program
{
static void Main(string[] args)
{
Employee emp = new Employee {Name = "Kisan",Id = 55,Department = "IT",salary = 20000};

}
}

It seems that we have saved a lot of Key strokes using this Object Initializer. So, this is also considered as a "Syntactic Sugar".

iv. Collection Initializers:

Collection Initializers are used to initialize a collection in a planned and advance manner to avoid lot of Key strokes:

namespace syntax_sugar
{
public class Employee
{
public string Name { get; set; }
public int Id { get; set; }
public string Department { get; set; }
public int salary { get; set; }
}
class Program
{
static void Main(string[] args)
{

List liemp=new List();
Employee emp = new Employee();
emp.Name = "Kumar";
emp.Department = "IT";
emp.Id = 101;
emp.salary = 80000;
liemp.Add(emp); //one object is added in the list

Employee emp1 = new Employee();
emp1.Name = "Abdul";
emp1.Department = "IT";
emp1.Id = 1010;
emp1.salary = 80000;
liemp.Add(emp1); //Second object is added in the List

}
}

Let's see how we can improve our coading quality using collection Initializers. Consider the following program for reference:

static void Main(string[] args)
{

List liemp = new List
{
new Employee {Name = "Kumar",Id = 101,Department = "IT",salary = 80000},
new Employee {Name = "Abdul",Id = 1010,Department = "IT",salary = 80000}

};
}

Conclusion:

Here, our main intention is to make you aware about Collection Initialization and Object Initiallization which are two important concepts discovered in C# 3.0, and let you know how these two important concepts are considered as syntactic sugar in progromming.

Hope you liked this article. If you have any doubts  and suggestation, please do comment so that I can update.