What is a Variable? A variable is a named container used to store data in a program. The stored value can be a number, string, object, array, or any other data type. Example: let name = " John " ; let age = 25 ; 1. var var is the oldest way to declare variables in JavaScript. It was used before the introduction of ES6 (ECMAScript 2015). Syntax var city = " Chennai " ; Characteristi...