Rules for creating JavaScript Variables!

There are some important rules to follow when naming variables in JavaScript:

• Variable names can only consist of letters, numbers, underscores (_) and dollar signs ($).

• Variable names must start with a letter, underscore or dollar sign. They cannot start with a number.

• Variable names are case-sensitive. myVariable and MyVariable are two different variables.

• It's good practice to use camelCase for variable names, where the first word is lowercase and proceeding words start with an uppercase letter.

• Avoid using JavaScript reserved keywords as variable names.

• Use meaningful names that describe the purpose of the variable.

Some examples of good variable names:

let firstName;
let userAge;
let $userName; 
let _privateVariable;

Here are some bad variable names:

let 5years; // Cannot start with a number
let name; // Too generic
let var; // 'var' is a reserved keyword

It's also a good practice to declare variables at the top of your code using let or const:

let firstName;
let lastName;

firstName = 'John';
lastName = 'Doe';

As much as possible, use const for variables that will never be reassigned:

const PI = 3.14;

Conclusion-

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