JavaScript is a text-based programming language used for making web pages interactive on both client-side and server-side. It allows manipulation of HTML content, attributes, styles, and elements, while offering advantages like speed, simplicity, and versatility, and disadvantages such as debugging issues and client-side security risks. Variables can be declared using 'var', 'let', and 'const', each with different scoping rules.

1. JAVASCRIPT
What is JavaScript
 JavaScript is a text-based programing language.
 It is used both on client-side and server-side. That allows you to make a web pages
interactive.
 HTML & CSS are languages that gives structure and style to web pages, JavaScript gives
web pages interactive elements that engage a user.
What can JavaScript can do?
o JavaScript can change HTML content.
o JavaScript can change HTML attributes.
o JavaScript can change HTML styles (CSS)
o JavaScript can hide html elements.
o JavaScript can show html elements.
Advantages of JavaScript?
 Speed
 Simplicity
 Popularity
 Interoperability
 Server load
 Rich interface
 Extended functionality
 Versatility
Disadvantages of java script?
 Cannot Debug
 Unexpected stop of rendering
 Client-side Security
 Inheritance
 Browser Support
Variables
Variable using 3 keywords that are var, let, and const.
1.Var: Global scoped or function scoped.
Redeclare & reassign.
<script>
var x= 10010;
// var x= 1001;
console.log(x);
</script>

2. 2.Let: let variable is only block scoped. It can’t be accessible outside the
particular block ({block}).
Reassign
<script>
let x= 10;
// console.log(x);
x= 20;
console.log(x);
</script>
3.Const: The scope of a const variable is block scope.
Redeclare & reassign.
<script>
const x= 10;
console.log(x);
const y=11;
console.log(y)
</script>
DATA TYPES: