Language Presentations

CSS

• CSS stands for Cascading Style Sheets
• CSS describes how HTML elements are to be displayed on the screen, paper, or in other media
• CSS saves a lot of work. It can control the layout of multiple web pages all at once
• External stylesheets are stored in CSS files

Advantage

1. Improved website speed
2. Consistency
3. Easy to maintain

Disadvantage

1. Come in different levels
2. Fragmentation
3. Lack of security

HTML

• HTML is the standard markup language for creating Web pages.
• HTML stands for HyperText Markup Language
• HTML describes the structure of a Web page
• HTML consists of a series of elements
• HTML elements tell the browser how to display the content
• HTML elements are represented by tags
• HTML tags label pieces of content such as "heading", "paragraph", "table", and so on
• Browsers do not display the HTML tags but use them to render the content of the page

Advantages

1. The first advantage it is widely used.
2. Every browser supports HTML language.
3. Easy to learn and use.
4. It is by default in every window so you don't need to purchase extra software.
5. You can integrate HTML with CSS, JavaScript, php etc.

Disadvantages 

1.  It can create only static and plain pages so if we need dynamic pages then HTML not useful.
2. I need to write a lot of code for making a simple web page.
3. Security features are not good at HTML.
4. If we need to write a long code for making a web page then it produces some complexity.

Html Codes 

1. <strong> - Bold
2. <i>  - Italic
3. <ins> - Underline
4. <del> - cross word
5. <mark> - highlight 
6. <small> - small text
7. <ins> - insert text
8. <sub> - subscript text 
9. <sup> - superscript
10. <b> - bold text

What are the differents of Html Vs Html5

• HTML5 supports both audio and video whereas none of these was a part of HTML
• HTML does not allow JavaScript to run within the web browser whereas HTML5 provides full support for JavaScript to run in the background.
• In HTML5, inline MathML and SVG can be used in text whereas this wasn’t possible in HTML.
• HTML5 supports new kinds of form controls, for example, dates and times, email, number, range, tel, URL, search, etc.
• There are many new elements introduced in HTML5. Some of the most important ones are: summary, time, audio, details, embed, figcaption, figure, footer, header, article, canvas, nav, output, section, source, track, video, etc

                                                                                                   REF: www.quora.com

Java Script 

• JavaScript is the Programming Language for the Web
• JavaScript can update and change both HTML and CSS
• JavaScript can calculate, manipulate and validate data

Advantages

• Speed. Client-side JavaScript is very fast because it can be run immediately within the client-side browser. Unless outside resources are required, JavaScript is unhindered by network calls to a backend server. It also has no need to be compiled on the client-side which gives it certain speed advantages (granted, adding some risk dependent on that quality of the code developed).

• Simplicity. JavaScript is relatively simple to learn and implement.

• Popularity. JavaScript is used everywhere on the web. The resources to learn JavaScript are numerous. StackOverflow and GitHub have many projects that are using Javascript and the language as a whole has gained a lot of traction in the industry in recent years especially.

• Interoperability. JavaScript plays nicely with other languages and can be used in a huge variety of applications. Unlike PHP or SSI scripts, JavaScript can be inserted into any web page regardless of the file extension. JavaScript can also be used inside scripts written in other languages such as Perl and PHP.

• Server Load. Being client-side reduces the demand on the website server

• Rich interfaces. Drag and drop components or slider may give a rich interface to your website.

• Extended Functionality. Third-party add-ons like Greasemonkey enable JavaScript developers to write snippets of JavaScript which can execute on desired web pages to extend its functionality.

• Versatility. Nowadays, there are many ways to use JavaScript through Node.js servers. If you were to bootstrap node.js with Express, use a document database like MongoDB, and use JavaScript on the front-end for clients, it is possible to develop an entire JavaScript app from front to back using only JavaScript.

• Updates. Since the advent of EcmaScript 5 (the scripting specification that Javascript relies on), Ecma International has dedicated to updating JavaScript annually. So far, we have received browser support for ES6 in 2017 and look forward to ES7 being supported in future months.

Disadvantages 

• Client-Side Security. Because the code executes on the users’ computer, in some cases it can be exploited for malicious purposes. This is one reason some people choose to disable Javascript.

• Browser Support. JavaScript is sometimes interpreted differently by different browsers. Whereas server-side scripts will always produce the same output, client-side scripts can be a little unpredictable. Don’t be overly concerned by this though - as long as you test your script in all the major browsers you should be safe. Also, there are services out there that will allow you to test your code automatically on check-in of an update to make sure all browsers support your code.  

           Ref:-  https://guide.freecodecamp.org/javascript/advantages-and-disadvantages-of-javascript

Python

Python is a popular programming language. It was created by Guido van Rossum, and released in 1991.

It is used for:

• web development (server-side),
• software development,
• mathematics,
• system scripting.

What can Python do?

• Python can be used on a server to create web applications.
• Python can be used alongside software to create workflows.
• Python can connect to database systems. It can also read and modify files.
• Python can be used to handle big data and perform complex mathematics.
• Python can be used for rapid prototyping, or for production-ready software development.

Why Python?

• Python works on different platforms (Windows, Mac, Linux, Raspberry Pi, etc).
• Python has a simple syntax similar to the English language.
• Python has a syntax that allows developers to write programs with fewer lines than some other programming languages.
• Python runs on an interpreter system, meaning that code can be executed as soon as it is written. This means that prototyping can be very quick.
• Python can be treated in a procedural way, an object-orientated way or a functional way.

Good to know

• The most recent major version of Python is Python 3, which we shall be using in this tutorial. However, Python 2, although not being updated with anything other than security updates, is still quite popular.
• In this tutorial, Python will be written in a text editor. It is possible to write Python in an Integrated Development Environment, such as Thonny, Pycharm, Netbeans or Eclipse which are particularly useful when managing larger collections of Python files.

Python Syntax compared to other programming languages

• Python was designed for readability and has some similarities to the English language with influence from mathematics.
• Python uses new lines to complete a command, as opposed to other programming languages that often use semicolons or parentheses.
• Python relies on indentation, using whitespace, to define scope; such as the scope of loops, functions, and classes. Other programming languages often use curly-brackets for this purpose.

 

Advantages

• Compared to other programming languages Python is the most broadly applied by the developers lately. Within the next paragraphs, we will take a look at the advantages of Python programming language for developers in contrast with other languages.

• The main Python language advantages are that it is easy to read and easy to learn. It is easier to write a program in Python than in C or C++. With this language, you gain the possibility to think clearly while coding, which also makes the code easier to sustain. Which reduces the cost for maintenance of the program and seen as one of Python programming advantages.\

• So, what are the advantages of Python that make this language special? The answer is that Python has some unique characteristics that are valuable for programmers because they make coding easier. Another advantage of Python programming is that no bug can originate a segmentation fault.

• An important advantage of Python language is that it has wide applicability, and is extensively used by scientists, engineers, and mathematicians. It is for this reason that Python is so useful for prototyping and all kinds of experiments. It is used in many groundbreaking fields. It is also used when producing animation for movies and in machine learning.

• The language includes a large library with memory management which is another one of the advantages of Python programming.

Disadvantages

• As an interpreted language, Python has a slow speed of execution. It is slower than C and C++ because it works with an interpreter, not the compiler.

• The language is seen as less suitable for mobile development and game development. It is often used on desktop and server, but there are only several mobile applications that were developed with Python. Another disadvantage Python has is the run time error. The language has a lot of design limits and needs more testing time. The programmer has the possibility to see bugs only during run time.

• Python has high memory consumption and is not used in web browsers because it is not secure. Language flexibility is considered among both the advantages and disadvantages of Python.

• Developers like Python for its simplicity in learning and coding, so much that it might be difficult for some of them to learn and use other languages.

• In spite of all the disadvantages of Python programming language, it has a lot more pros than cons.

SQL

• SQL is a standard language for accessing and manipulating databases.

What is SQL?

• SQL stands for Structured Query Language
• SQL lets you access and manipulates databases
• SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standardization (ISO) in 1987

What Can SQL do?

• SQL can execute queries against a database
• SQL can retrieve data from a database
• SQL can insert records in a database
• SQL can update records in a database
• SQL can delete records from a database
• SQL can create new databases
• SQL can create new tables in a database
• SQL can create stored procedures in a database
• SQL can create views in a database
• SQL can set permissions on tables, procedures, and views

Some of The Most Important SQL Commands

• SELECT - extracts data from a database
• UPDATE - updates data in a database
• DELETE - deletes data from a database
• INSERT INTO - inserts new data into a database
• CREATE DATABASE - creates a new database
• ALTER DATABASE - modifies a database
• CREATE TABLE - creates a new table
• ALTER TABLE - modifies a table
• DROP TABLE - deletes a table
• CREATE INDEX - creates an index (search key)
• DROP INDEX - deletes an index

Advantage 

• You don’t need any coding in SQL. This means by using standard SQL you can easily manage database systems, no need to write a substantial amount of code.

• It is Portable. By this term, I mean to data portability. SQL supports PCs, laptops, tablets, servers, mainframes. We can run SQL on a local system with an intranet and internet. We can easily move the database using SQL from one device to another.

• Well Defined Standards. SQL database uses an established standard, that is being used by ANSI (American National Standard Institutes) and ISO (International Organization for Standardization).

• Multiple Data Views. Using SQL language users can make different views of the database structure for the different users.

• Interactive Language. We can use this language for communication with the database. With this, we can get answers to complex queries in a few seconds.

Disadvantages 

• Partial Control. Due to the hidden business rules, programmers using SQL doesn’t have full control over the database.

• Cost. There are some SQL versions which have high operating cost, so it creates difficulty for some programmers to access those versions.

• Interface. SQL has a complex interface that creates difficulty for some users to access it.

                                               Most of the reference are:- https://www.w3schools.com/

Node.JS

What is Node.JS

• Node.js is an open source server environment
• Node.js is free
• Node.js runs on various platforms (Windows, Linux, Unix, Mac OS X, etc.)
• Node.js uses JavaScript on the server

Why Node.js?

• Node.js uses asynchronous programming!
• A common task for a web server can be to open a file on the server and return the content to the client.
• Here is how PHP or ASP handles a file request:
• Sends the task to the computer's file system.
• Waits while the file system opens and reads the file.
• Returns the content to the client.
• Ready to handle the next request.

Here is how Node.js handles a file request:

• Sends the task to the computer's file system.
• Ready to handle the next request.
• When the file system has opened and read the file, the server returns the content to the client.
• Node.js eliminates the waiting and simply continues with the next request.
• Node.js runs single-threaded, non-blocking, asynchronously programming, which is very memory efficient.

What Can Node.js Do?

• Node.js can generate the dynamic page content
• Node.js can create, open, read, write, delete, and close files on the server
• Node.js can collect form data
• Node.js can add, delete, modify data in your database

                                                                        Download Link:-  https://nodejs.org

Advantages of Node.js

1. Easy Scalability
2. Easy to Learn
3. Full-Stack JS
4. Higher performance
5. Huge and Active Community
6. Single programming language
7. Freedom to Develop Apps
8. Process Several Request simultaneously
9. Extended support
10. It’s faster

Disadvantage of Node.JS

1. API Interface is not stable
2. The library is nothing good to write home about
3. Not good for heavy computation
4. Not good with relational databases
5. Being an Asynchronous Programming Model