Free Fire More JavaScript Concepts
Tags: beginners, javascript, tutorial
Published: 2021-12-20 15:58:16

Hello _Everyone_, Today We Will Discuss About SOME JS Concepts. We Have a Perfect Name For This BLOG, Which is called, Free Fire CSS Concepts. Sound Cools. Because There Are Lot Of GAMERS, I Know BUT, Today Topic is not Gaming, Something Crazy. Because We Will Clear Some Concepts Here. **Let's Start**

---

### ES6 features
ES6 or the ECMAScript 2015 is the 6th and major edition of the ECMAScript language specification standard. ES6 brought significant changes to the JavaScript language. It introduces several new features such as, let and const Keywords, Arrow Functions, Multi-line Strings, Default Parameters, Template Literals, Destructuring Assignment, Enhanced Object Literals, Promises, Classes, Modules. Whenever I Code, That Time, I Just Try To Use All OF Them In My Project.

```
- let and const Keywords
- Arrow Functions
- Multi-line Strings
- Default Parameters
- Template Literals
- Destructuring Assignment
- Enhanced Object Literals
- Promises
- Classes
- Modules
```

---

### Differences between var, let, and const
From ES6, There are Three Variables, var, let and const. 
var declarations are globally scoped or function scoped while let and const are block scoped and all of these are functional scoped. Const can’t be reassigned while let & const can be reassigned.

```
var x = "John Doe";
var x = 0;
```

```
let x = "John Doe";
let x = 0;
// SyntaxError: 'x' has already been declared
```

```
const PI = 3.141592653589793;
PI = 3.14;      // This will give an error
```

---

### JavaScript scope, Block scope, and global scope
A scope defines the lifetime visibility of a variable. Scope in JavaScript defines accessibility of variables, objects and functions. A block scoped variable means that the variable defined within a block will not be accessible from outside the block. And Global variables can be accessed from anywhere in a JavaScript program.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/l39raid85lglfesnm3x2.png)
 

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### API in JavaScript
API stands for application programming interface. API is a software intermediary that allows two applications to talk to each other. GET is used to request data from a specified resource And POST is used to send data to a server.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/nd7n8sy4jclgpac23xs4.png)

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### How JavaScript code can be involved in an HTML file
You can include JavaScript in your HTML in Three Ways. 
Inline, Internal, External. 
In Inline, We can write JS in HTML Tag Line. And Internal, We can Add <script> </script> Tag at The Bottom OF HTML Document And we can write JS There. And Of Course, We can Link A File And USE It Like External JS. 



---

### Array vs LinkedList
The Main Difference Between Array And LinkedList is Their Structure.  Array elements store in a contiguous memory location. Linked list elements can be stored anywhere in the memory. From a memory allocation, linked lists are more efficient than arrays.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/49j52vyxoijyux59jdme.png)