Intro to Modern Js Es6 (1) Variables, newKeyWords & Data Types in one code file !

Hoo-Ah , Welcome in this article i'd like to talk about new JS's features for Beginners , we will start with Variables,Js's newKeyWords & Data Types

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in this series i'll give some kind of A brief explanation
within one JS Code file that Contains the majority of the
most common cases that use vars and datatypes and how results
looks in Browser Console! just read one time

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            Code written by Abd-Elrahman 

 /* 
    JavaScript intro 
    Variables, newKeyWords & Data Types
*/

// How To log some data to Console Window
console.log('hell FROM CONSOLE ');

// variable and constants 

// use let keyWord
let age = 10;
let year = 2020;
console.log(age,year);

// overRide age variable 
age = 30; 
console.log(age) // age is 30 now


//Use const keyWord 
const points = 100 ;
console.log(points); // The output is 100

// Try to overRide Points constant 
// OverRidden cann't be done with a Constant 
// points = 200;
// console.log(points) // Uncaught TypeError: Assignment to constant variable.
/* 


// Data Types in Javascript 
Number => 1,2,3,177
String => 'hello world' , "Abdelrahamn Mohamed"
Boolean => true / false
Null => Explicitly set a variable with no value
Undefined => For variables that have not been defined
Object => Complex data structures - arrays,Dates,Literals etc
Symbol => Used with objects
*/


// Strings
console.log('hello world');

let email = '[e-mail]';
console.log(email); // [e-mail]


// string concatenation
let firstName = 'Abdelrahman';
let lastName = 'Mohamed';
let fullName = firstName + ' ' + lastName;
console.log(fullName);

// getting characters
console.log(fullName[0]);  // output is A

//string lenght
console.log(fullName.length); //19

//string methods
console.log(fullName.toUpperCase()); //ABDELRAHMAN MOHAMED
console.log(email.indexOf('@')); // 11
console.log(fullName.lastIndexOf('n')); // give us the position of last 'n' in the full name
console.log(fullName.slice(0,11)); // gine us the part from 0 to 11 .SO it returns Abdelrahman 
console.log(fullName.substr(0,11)) // this one is like slice(), ut the second argument represent the how many chars we want to cutoff
console.log(fullName.replace('A','a')) // Abdelrahman



// Numbers
let raduis = 10;
const pi = 3.14;

// math operators + - * / ** %
// order of operation - B I D M A S 
let result = pi * raduis**2
console.log(result)

let likes = 10 ; 
likes = likes + 1; //11
//short hand vesrion 
likes++; //11 , itis adding one 
likes += 10 ; // 20  here we add 10 to number of likes wich is 10 so it's 20
likes -= 5 ; // 15 
likes /= 2 ; // 20

console.log(5/'hello'); // NaN means not a number 
console.log('the blog has' + likes + 'likes'); // the blog has 10 likes 

// template strings
const title = 'Intro to JavaScript';
const author = 'Abdelrahman';
const views = 30;

// concatenation way 
let output = 'the blog called ' + title + ' by ' + author + ' has '  + views + ' views'; 
console.log(output); //the blog called Intro to JavaScript by Abdelrahman has 30 views

// template string way 
let out = `the blog called ${title} by ${author} has ${views} views`;
console.log(out); //the blog called Intro to JavaScript by Abdelrahman has 30 views

// creating html templates
 let html = `
 <h2>${title}</h2>
 <p>${author}</p>
 <span> this blog has ${views} views </span>
 `;
 console.log(html);

 // The End for now ! :)

    ```


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Thanks in advance 
rahmanii