30 Days Javascript Challenge (by Hitesh Choudhary) Day 1 - Variables and Data Types

First you can visit to the Assignment or I put the screenshot of same here:
https://courses.chaicode.com/learn/home/30-days-of-Javascript-challenge/30-days-javascript-challenge/section/515627/lesson/3196994

Task 1:

var is used for declaring a variable or we can say that the value is being assign to the variable.

Example:

var myNumber = 3;
console.log(myNumber); // Output: 3

Task 2:

let is also used to declare a variable, same as of var.
The difference between let and var is in the scope of the variables they create: Variables declared by let are only available inside the block where they're defined. Variables declared by var are available throughout the function in which they're declared.

Example:

let myName = "Alpit";
console.log(myName); // Output: Alpit

Task 3:

When we use const for a declaration of a variable, we can't assign another value, as it is possible in let and var.

Example:

const codemore = "true";
console.log(codemore); // Output: true

Task 4:

Mainly there are total 5 Data types in Javascript.

Example:

let num = 4;
let str = "Javascript 30 Days Challenge";
let checking = "false";
let object = { name: "Alpit", age: 20 };
let arr = [1, 2, 3, 4, 5];

console.log(typeof num);      // Output: number
console.log(typeof str);      // Output: string
console.log(typeof checking); // Output: string
console.log(typeof object);   // Output: object
console.log(typeof arr);      // Output: object

Task 5:

When we redeclare the variable which was initially defined using let, it's value can be changed later.

Example:

let myVariable = 10;
console.log(myVariable); // Output: 10

myVariable = "Hello World";
console.log(myVariable); // Output: Hello World

Task 6:

When we reassign the value to the const variable, it gives the error.

Example:

const myConstant = 100;
console.log(myConstant); // Output: 100

// Trying to reassign will cause an error
myConstant = 200;
console.log(myConstant); // Uncaught TypeError: Assignment to constant variable.

Feature Request

1. Variable Types Console Log

Example:

let numberVar = 25;
let stringVar = "This is a string";
let booleanVar = true;
let objectVar = { key: "value" };
let arrayVar = [1, 2, 3];

console.log(`Value: ${numberVar}, Type: ${typeof numberVar}`); // Output: Value: 25, Type: number
console.log(`Value: ${stringVar}, Type: ${typeof stringVar}`); // Output: Value: This is a string, Type: string
console.log(`Value: ${booleanVar}, Type: ${typeof booleanVar}`); // Output: Value: true, Type: boolean
console.log(`Value: ${objectVar}, Type: ${typeof objectVar}`); // Output: Value: [object Object], Type: object
console.log(`Value: ${arrayVar}, Type: ${typeof arrayVar}`); // Output: Value: 1,2,3, Type: object

2. Reassignment Demo:

Example:

let reassignableVar = "Initial value";
console.log(reassignableVar); // Output: Initial value

reassignableVar = "New value";
console.log(reassignableVar); // Output: New value

const constantVar = "Fixed value";
console.log(constantVar); // Output: Fixed value

// Trying to reassign will cause an error
constantVar = "Attempt to change"; // Uncaught TypeError: Assignment to constant variable.