What is Variable | How to declare var in JS

Опубликовано: 20 Январь 2025
на канале: AmsR HuB

What is a Variable?

In programming, a variable is a named storage location that holds a value. Variables allow you to store and manipulate data in your code.

Types of Variables in JavaScript:

1. Numeric (Number)
2. String (Text)
3. Boolean (True/False)
4. Array (Collection of values)
5. Object (Collection of key-value pairs)
6. Null (No value)
7. Undefined (Uninitialized)

Declaring Variables in JavaScript:

There are three ways to declare variables in JavaScript:

1. Var

`var variableName = value;`

Example: `var name = 'John';`

2. Let

`let variableName = value;`

Example: `let age = 25;`

3. Const

`const variableName = value;`

Example: `const PI = 3.14;`

Key differences:

`var`: Function scope, can be redeclared.
`let`: Block scope, cannot be redeclared.
`const`: Block scope, cannot be redeclared or reassigned.

Variable Naming Rules:

1. Start with a letter, underscore (_), or dollar sign ($).
2. Contain only letters, numbers, underscores, and dollar signs.
3. Avoid reserved keywords.
4. Be descriptive and concise.

Variable Scope:

Global: Accessible anywhere in the code.
Local: Accessible only within a function or block.
Function: Accessible only within a function.

Example Code:
```
// Declare variables
var name = 'John';
let age = 25;
const PI = 3.14;

// Assign values
name = 'Jane';
age = 30;

// Console output
console.log(name); // Jane
console.log(age); // 30
console.log(PI); // 3.14
```

📒 Get Notes here:
https://chat.whatsapp.com/GLJ3nFxD3K72cC2v...
🧑🏻‍💻 Get Code here: https://github.com/Aryan0-1Maurya

📌 Bookmark this Playlist:
   • Javascript Mastery | Js for Beginners...

   • Web Development | Full Stack | 10 to ...

🥳 Join our WhatsApp Community:
WhatsApp group: https://chat.whatsapp.com/GLJ3nFxD3K72cC2v...

🚀 Follow me on:
Instagram: https://www.instagram.com/amsrhub01/
Linkedin: https://www.linkedin.com/in/aryan-maurya-6...
GitHub:
https://github.com/Aryan0-1Maurya
Codepen:https://codepen.io/aryan-maurya-amsr/
Facebook:https://www.facebook.com/profile.php?id=10...
Group:https://chat.whatsapp.com/GLJ3nFxD3K72cC2v...
YouTube:   / @amsr-hub
Linktree: https://linktr.ee/amsrhub

Hashtags:
#variable #javascriptdev #js #let #const #vqr

Ignore these Tags:

web development full course
web development amsrhub
web development roadmap
web development
aryan maurya
roadmap for web development
Javascript full course
animation in js
Javascript in web development
beautiful website in web development
Js basics
Javascript in one video
full stack web development course
web development course
web development roadmap 2024
web dev roadmap 2025
amsr hub css
Js asmr hub
aryan sir js coding
front end developer roadmap
anuj bhaiya web development
full stack developer roadmap
full stack web development roadmap
web development roadmap 2024
web developer roadmap
roadmap to web development
backend web development
best web development course
web designing full course
code with harry web development course
apna college web development
web development full course in hindi
website development
frontend developer roadmap
web development projects
front end developer course
traversy media web development
full stack web development
full web development course
full stack developer
how to learn web development
complete web developer course
roadmap for front end developer
web development anuj bhaiya
complete roadmap for web development
what is web development
full stack developer course
front end web development full course
web development road map
web developer course
backend developer roadmap
web developer roadmap 2024
android development
front end developer
complete web development course
front end roadmap
love babbar web development
web dev
javascript roadmap
roadmap
love babbar web development roadmap
front end development tutorial
web development tutorial
website development course
roadmap of web development
web developer
aman dhattarwal web development
javascript full course
web development for beginners
android development roadmap
java web development
web devlopment
html full course
web development code with harry
web development tutorial for beginners
javascript tutorial
web development projects
web development projects for beginners
web development projects for final year
web development projects for resume
web development project
projects for resume
mern stack projects for resume
web dev projects
full stack project
full stack web development project
project ideas for web development
projects for placements
mern project
front end projects
web development
web development project ideas
project for placement
web dev projects for resume
java projects
project on web development
projects on web development
best web development projects
project ideas
web projects
mern stack project
website ideas for project