Interview series 01-"Understanding JavaScript Variable Declarations: var Let, and const
var, let, and const are three different ways to declare variables in JavaScript, each with its own scope and mutability characteristics.
var: Prior to ES6 (ECMAScript 2015), var was the primary way to declare variables in JavaScript. Variables declared with var have function scope or global scope if declared outside of a function. They can be redeclared and reassigned within their scope.
let: Introduced in ES6, let allows for block-scoped variables. Variables declared with let are limited in scope to the block, statement, or expression on which it is used. Unlike var, variables declared with let cannot be redeclared within the same scope, but they can be reassigned.
const: Also introduced in ES6, const declares variables with block scope like let, but with the added constraint that the variable's value cannot be reassigned after initialization. However, for objects and arrays, the values they hold can be modified, but the variable itself cannot be reassigned to a different value.
In summary, var is function-scoped, let is block-scoped and allows reassignment, while const is also block-scoped but does not allow reassignment of the variable itself after initialization. They offer flexibility and help in writing cleaner and more predictable code.