How to declare variable in Javascript?

How to declare variable in Javascript?
Variables are used to store data in memory. JavaScript variables are declared with the var keyword.

var empname;

Multiple variables can be declared in a single step.
var empname, age, weight, gender;

After a variable is declared, it can be assigned a value.
empname = 'nathan';

Variable declaration and assignment can be done in a single step.
var empname = 'nathan';