In this article , we will look through all the topics which is related with JavaScript.JavaScript is a client-side scripting language which is commonly used to create interaction with html documents.

In JavaScript, there are nine data types where six types are primitive and three types are non-primitive. Primitive data types are Number , boolean , String , Undefined, BigInt and Symbol. Null(spacial primitive),Object and Function are non-primitive data-types. there are three ways to declare variables. Those are var,let , const where var is a global object.On the other hand let and const work in the block scopes.

There are various types of operator are used in JavaScript.Those are unary operator, assignment operator , logical operator , comparison operator.Unary operators take single operand and perform operation. The Unary operators in JavaScript are unary plus(+), unary minus(-), prefix/postfix increments(++) and prefix/postfix decrements.The basic assignment operator is(=). Logical operators including the logical NOT operator( !), the logical AND operator ( &&) and the logical OR operator ( || ).It allows you to compare variable. In comparison operator it compare two variables and it returns a boolean value true or false. Those comparison operators are less than(<),greater than(>),less than or equal to(≤), greater than or equal to(≥), equal to(==) and not equal to(!=).

JavaScript Control Flow:

if else statement, switch case, for, while,do while, break, continue all are used in control flow statement because those things take actions based on condition.

JavaScript String:

JavaScript string are primitive values.And it also immutable.That means if you process a string ,you will always get a new string.The original string doesn’t change.The String type is object wrapper of the string primitive values and can be created by using the String constructor . let str = new String(“JavaScript String”). The String type provides lots of method for manipulating string.Few of them are charAt(),concat(),includes(),endswith(),indexOf(),lastIndexOf(),replace() , slice(),split(),substr(),toLowercase(),toUppercase(),trim().

JavaScript Array:

In JavaScript, an array is an ordered list of data.The array provides lots of method for manipulating array data.Some of them are map(),reduce(),find(),filter(),every(),length,reverse(),pop(),push(),slice() , shift(),join(),forEach(),indexOf(),for …of,sort() etc

JavaScript Functions:

To avoid repeating the same code all over places, you can use a function to wrap that code and reuse it.Some build-in functions like alert(),console.log() we can create custom function.Functions in JavaScript are first-class objects, which means you can store functions in variables. pass them to other functions as arguments, and return them from other functions as values. Various custom functions like immediately invoked function expression(IIFE) , callback function anonymous function.

JavaScript Object: In JavaScript, an object is a collection of properties, defined as a key-value pair. Each property has a key and a value. Some topics like object properties,object creation pattern, prototypes,prototypal inheritance,this keyword should be cover .Object can be manipulated .Using loop,create(),assign,freeze(),keys,seal(),value()

JavaScript Error handling:

try..catch is mainly a error handling way.It constructs with two blocks.When the code runs at that time only ‘try’ block works and ignores ‘catch’ block.If any error occurs,the try execution is stopped, and control flows to the beginning of catch(err).Besides try..catch..finally, throw operator,custom error is included in JavaScript.

JavaScript Runtime:

Execution context .call stack, hoisting,variable scopes,Event loop all topics are related with JavaScript.Using those topics we can understand how JavaScript interpret the code.

JavaScript DOM:

The Document Object Model (DOM) is an application programming interface (API) for manipulating HTML and XML documents.The DOM represents a document as a tree of nodes. It provides API that allows you to add, remove, and modify parts of the document effectively. Selecting elements,Traversing elements,Manipulating elements,working with Attributes,Manipulating Elements’s Styles, Working with Events,Scripting web form.

Javascript ES6 :

ECMAScript 2015 or ES2015 us a significant update in JavaScript.ES2015 is often called ES6.let ,const, default function parameters,Rest operator, Spread operator,Object literal syntax extension,for..of,template literals, Destructuring,ES6 modules, ES6 class,arrow function,iterators & generators,Promise,ES6 collections(Map,set)


The Storage interface of the Web Storage API provides access to a particular domain's session or local storage. It allows, for example, the addition, modification, or deletion of stored data items.To manipulate, for instance, the session storage for a domain, a call to Window.sessionStorage is made; whereas for local storage the call is made to Window.localStorage.Property like storage.length and method storage.getItem() , storage.setItem() , storage.removeItem,storage.clear() .

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Web developer