Total cost is undefined. The reduce function is missing a return statement. The reduce function should return the accumulator after the iteration is complete.

const products = [
  { name: "Shirt", price: 20, discount: true },
  { name: "Pants", price: 50, discount: false },
  { name: "Hat", price: 15, discount: true },
  { name: "Socks", price: 5, discount: true },
];

const discountThreshold = 30;
const discountRate = 0.1;

const totalCost = products.reduce((acc, product) => {
  if (product.discount) {
    if (product.price > discountThreshold) {
      acc += product.price * (1 - discountRate);
    } else {
      acc += product.price;
    }
  } else {
    acc += product.price;
  }
  return acc;
}, 0);

console.log(`Total cost: ${totalCost}`);