INHERITANCE AND CONSTUCTOR CONCEPTS

10th Day                                                                                                                          

                                                                                                                   

 Hey Guys ,I hope that you are enjoying with my blogs writing and today's we 

 will cover some concepts:

                                                    

          INHERITANCE :   

• Inheritance is an aspect of OOPs languages.
• which provides the ability of a program to create a new class from an existing class.
• The class whose members are inherited is called the base class, and the class that inherits those members is called the derived/child/subclass. In child class, we can override or modify the behaviors of its parent class.
• Syntax:

                    Parent class :

                          

                          class <Class_name>

                                {

                                   // methods and fields

                                 }

•  Example:

                      

                            Child class:

                          class sub_class_name extends super_class_name  
                           {  
                              // methods and fields  
                           {

•  Example:

                    

• We can use it for Code Reusability.
• We can use it for Method Overriding.
• This is called IS RELATIONSHIP i.e. Customer IS A CHILD OF  Lead.

                    

• Using import and export method we have created parent-child relationship.
•  Example:

                   

         TYPES OF INHERITANCE:  

• Single Inheritance: it can inherit properties and behavior from at most one parent class.
• Multilevel Inheritance: In this case a derived class is derived from another derived class.
• Multiple Inheritance :When an object or class inherits the characteristics and features form more than one parent class.
• Hierarchical Inheritance:  In this case, More than one subclass is inherited from a single base class.
• Hybrid Inheritance: In this case, A class inherits the characteristics and features from more than one form of inheritance.

                 

   

 

           CONSTRUCTOR:    

• A Constructor is a special type of function of typescript class and it will be automatically invoked when the first object of class is created.
• TypeScript only allows one constructor implementation.
• Suppose, In above Example we have required default values like address or anything.
• For Example: We have created two  class Lead & Customer  in Customer.ts .
• Customer.ts: 

                

• Now here ,we have created  Client.ts which will invoke Customer and Lead class :

              

• After Compilation: Using tsc -- init

               

• So here tsconfig.json file has been created successfully like Example:

                       

    

•  Just Run Client.js file through teminal: node Client.js  address will give as output.

             

• Suppose if it has constructor in parent class then first fire it.

             Access Modifiers public private and protected :             :

• Public: It is accessible outside or anywhere the class.
• Private: it is only accessible inside the class.
• Protected: It is only accessible in inherited classes and own classes we can't access outside.

                   

• So friend If you have any mistakes in any articles you can send me on my email:1809raushan@gmail.com.

                                                                                Thank You...