Trie questions

`Array.prototype.entries` returns a new Array Iterator object that contains the key/value pairs for each index in the array. It allows iteration over the array's indices and values. 

const arr = ['a', 'b', 'c'];
const iterator = arr.entries();
for (const [index, element] of iterator) {
  console.log(index, element);
}
// Output:
// 0 'a'
// 1 'b'
// 2 'c'

`Array.prototype.includes` determines whether an array contains a certain value among its entries. It returns `true` if the array contains the value, otherwise `false`. 

const arr = [1, 2, 3];
console.log(arr.includes(2)); // true
console.log(arr.includes(4)); // false

`String.prototype.match` retrieves the matches of a string against a regular expression. It returns an array of matches or `null` if no matches are found. 

const str = 'hello 123';
const matches = str.match(/\d+/);
console.log(matches); // ['123']

`get_object_or_404` is a Django shortcut function used to retrieve an object from the database based on a query. If the object is not found, it raises an `Http404` exception, which results in a 404 error page being displayed. This function simplifies error handling for common cases where an object must exist.

The `get_list_or_404` function is a Django shortcut used to fetch a list of objects from the database. If the query returns an empty list, it raises an `Http404` exception, resulting in a 404 error page. This function simplifies the handling of cases where you expect multiple objects but want to handle the absence of objects gracefully.

Stripe's API for managing customers allows you to create and manage customer records, including storing payment methods, subscriptions, and other customer details. Using the Customers API, you can create new customers, update their information, and retrieve customer data for use in billing and reporting. This API integrates with other Stripe services, such as Subscriptions and Invoicing, to provide a comprehensive customer management solution.