First program in javaScript (lt.30)

We will run the JavaScript programs in node.js which a run time environment for JavaScript , please try to avoid the window console as it can hamper the result and your ability to learn js in long run.

so install node.js and code with me :

just like printing any data to screen we use different syntax such as printf in c , cout in c++,

in JavaScript we use : console.log( value to be printed)

Variable : It is a type of container which is used to store value in ram for a particular time limit , so that it can be accessed easily .

Data types in Js:

1. Primitive data types: they are core foundational data types.

number : 3 , 5.7 ; string: "aa" , 'hii' ; Boolean : true , false ; Null: means nothing not zero ; Undefined: ; Symbol : used to create unique identifiers for object properties ; BigInt: large numbers.

2. Non primitive types:

array , objects

Keywords to be used in js:

1. let :Variables declared with let are block-scoped, meaning they are limited in scope to the block in which they are defined

2. const : Variables declared with const are also block-scoped. They cannot be reassigned once they are assigned a value.

3. var : we don't use var as it has many problems including the scope problem

   Try to prefer const more in long run.

   Program to demonstrate with it-

console.log("hello")

// console.log(this)
//if we print 'this' in console then it will give someoutput but in  case of actual code editor ans is null


// undefined
let a

const sym = Symbol("this is symbol")
console.log('symbol : ', sym)

// Array
let names =["himanshu" , 'hii', 7 , false]
console.log(names)

// object 
// object is an important concept in js

const person = {
    name: 'captain',
    age: 30,
    occupation: 'Engineer'
};

console.log(person.age)


// let
let x = 120;
console.log(x);

// var
var t = 10;
console.log(t);


// const
const z = 20;
console.log(z); 


//  //  a simple program

let price = 200;
console.log("price = ", price);
let gst = 0.18;
console.log("gst = ", gst);
console.log("coursePrice = ", gst * price + price);
console.log("coursePrice = ", gst * price - price);

lt.28: https://hashnode.com/post/clt7gt67800030al680fnbt1k