Variables & Data Types

var PI = 3.14;
let PI = 3.14;
const PI = 3.14;
The correct way to declare a constant in modern JavaScript is using the 'const' keyword: const PI = 3.14;. This was introduced in ES6 (2015) and creates a variable whose value cannot be reassigned. The 'var' and 'let' keywords create variables that can be reassigned. There is no 'constant' keyword in JavaScript.
constant PI = 3.14;