3. 3
• What is DOM?
• What is API?
• What is Js?
• European Computers Manufacturers Associations
• Variable Declaration
• Function Declaration
• Sync/Async
• Node Package Manager
4. The name derivation and how it was
born:
• At First webpage had only DOM.
• Initially it was named as Mocha then to LiveScript
and finally JavaScript.
• Microsoft created it’s own version of Js and named it
Jscript (Internet explorer).
• ECMA finally came to conclusion on naming it
JavaScript.
4
5.
6. A Document Object Model
It is a programming interface that allows us to create,
change, or remove elements from the document. We
can also add events to these elements to make our page
more dynamic.
• Window object − Top of the hierarchy. It is the
outmost element of the object hierarchy.
• Document object − Each HTML document that gets
loaded into a window becomes a document object.
The document contains the contents of the page.
6
Ps : He is calling his family
8. 8
• Js is a client side scripting language.
• Interpreter language : Line by line compilation, Needed every time when we run the program, Returns list of error found
on which line.
• What is ECMA ?
It is expanded as European Computer Manufacturers Association, They set the standards in technology world. ES6 or ECMAScript 6 is a
scripting language specification which is standardized by ECMAScript International. This specification governs some languages such
as JavaScript, ActionScript, and Jscript. ECMAScript is generally used for client-side scripting, and it is also used for writing server
applications and services by using Node.js.
14. Application programming interfaces, or APIs, simplify software development and innovation by
enabling applications to exchange data and functionality easily and securely.
REST API
• The cost of communication is comparatively higher
than WebSocket.
• Lots of getting request.
• HTTP is a common protocol in RESTful web
WEBSOCKETS
• The cost of communication is lower.
• Real-time chat application.
• The use of HTTP occurs in the initial connection.
14
17. BIG IMAGE
When we try to render something from server we receive a html,
css and a js file.
17
18. 18
npm is a package manager for the JavaScript
programming language. It is the default package
manager for the JavaScript runtime environment
Node.js. It consists of a command line client, also
called npm, and an online database of public and
paid-for private packages, called the npm
registry.
