Var, Let, or Const?
· 4 min read
Understanding variable declarations is foundational to writing robust, bug-free JavaScript. Before ES6 (ECMAScript 2015), var was our only choice. Today, we have let and const and picking the wrong one can lead to silent errors, scope leaks, and unpredictable behavior.
In this guide, we will break down scope, hoisting, re-assignment rules, and the Temporal Dead Zone (TDZ) with visual mental models and interactive examples.