JS Const

Using const

Declare constants with const. These must be initialized at declaration and cannot be reassigned.

Immutability and Scope

Const variables are block-scoped and immutable for primitive values. For objects and arrays, the binding is constant but properties or elements can change.

Examples

const PI = 3.14;
const arr = [1,2,3];
arr.push(4);  // Allowed
// PI = 3.1415; // Error