rest-parameter.js

// Example 1
const order = [20.17, 18.67, 1.50, "cheese", "eggs", "milk", "bread"];
const [total, subtotal, tax, ...items] = order;
console.log(total, subtotal, tax, items);  // 20.17 18.67 1.5 ["cheese", "eggs", "milk", "bread"]

// Example 2
function sum(...nums) {
  let total = 0;  
  for(const num of nums) {
    total += num;
  }
  return total;
}
console.log(sum(10, 20, 30));  // 60
console.log(sum(20, 20));  // 40