What are Variables in JavaScript?

If you are interested in becoming a JS master or a complete web developer then you know about the important concepts of JavaScript without any doubt. 

Variables come in the same list of concepts. Theses are known as container to store some value in JavaScript. The main goal of variable declaration is to keep the necessary data in memory as variable so that we may use them through out our programme to carry out any task or action or action. 

Once a variable is declared, it can be used in a programme by referencing its name and appropriate data type.

Before we move further; it is recommended to start learning JS from the very beginning and for this you can enrol yourself in a web design institute in Delhi where you can learn under the career-oriented web development courses.

In JavaScript we have two types of variable:

Global Variable:Global variables, on the other hand, are those that are defined outside of functions. Because of their global scope, these variables can be utilised by any function without being sent to it as parameters.

Local Variable:Local variables are those that are defined within of functions while using javascript. They are only used within the functions that define them because of their local scope.

When declaring a javascript variable, there are several guidelines (also known as identifiers).

1. Name      must begin with an alphabetical letter (from A to Z), an underscore      (_), or a dollar sign($).      
2. The      first letter can be followed by any number from 0 to 9, such as      value 1.      
3. Javascript      variables are case-sensitive, for instance, the variables x and x      are distinct.

There are three types of variable keywords

Let: A block variable in JavaScript is declared with the let keyword. In JavaScript, the var keyword is typically used to declare a variable. Although variables declared using the let keyword are block scoped and are handled as regular variables.

For example:

let fname = "Alina";let lname = "Qutra"function fullName(){  console.log(fname + " " + lname);}fullName();

Var: var is a keyword for stating a value. It was first used in 1995. Two new keywords, let and const, were then added in Es6.

Const:Const variable names cannot be redeclared or reassigned. For example, If we want to use a password on our website and don’t want to change it, we can save it in a const variable because if we accidentally declare the same variable name, an error will result.

For example:

const password = "34375";password = "233434"console.log(password); Value of password can not be changed at the time of execution. 

In order to get all of these concepts of variable in a right way; it is must to learn them from scratch and to do so you need to pursue the following programs:

Go for the advanced JavaScript Classes in Delhi which covers 4 months long training under the guidance of web expertsYou can also try 3 months long program to attain industry oriented JavaScript Training in Rohini

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