Description:

Understanding the differences between let, const, and var helps prevent variable-related bugs in JavaScript.

Explanation:

• var: Function-scoped, hoisted, can be redeclared.

• let: Block-scoped, not hoisted, can be reassigned.

• const: Block-scoped, cannot be reassigned.

Example:

var a = 10;
let b = 20;
const c = 30;

a = 15; // Allowed
b = 25; // Allowed
// c = 35; // Error: Assignment to constant variable