check questions

`Array.prototype.includes` checks if an array contains a specified element and returns `true` if it is found, otherwise `false`. It is case-sensitive and supports an optional starting index. 

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

`String.prototype.includes` checks if a string contains a specified substring. It returns `true` if the substring is found, otherwise `false`. 

const str = 'hello';
console.log(str.includes('ell')); // true
console.log(str.includes('world')); // false

`String.prototype.endsWith` checks if a string ends with a specified substring and returns `true` if it does, otherwise `false`. 

const str = 'hello';
console.log(str.endsWith('lo')); // true
console.log(str.endsWith('he')); // false

`String.prototype.startsWith` checks if a string starts with a specified substring and returns `true` if it does, otherwise `false`. 

const str = 'hello';
console.log(str.startsWith('he')); // true
console.log(str.startsWith('lo')); // false

TypeScript is a statically typed language that builds on JavaScript by adding optional types. It allows developers to catch errors at compile time rather than runtime, which can help improve code quality and readability. TypeScript code is transpiled to JavaScript, making it compatible with existing JavaScript codebases and environments.

Angular's `ChangeDetectionStrategy` is a configuration that controls how Angular checks for changes in the application state and updates the view. There are two main strategies: `Default` and `OnPush`. The `Default` strategy checks all components in the component tree whenever an event or change occurs, ensuring that the view is updated accordingly. The `OnPush` strategy, on the other hand, limits change detection to components with changed input properties or events that originate from within the component. This can improve performance by reducing the frequency of change detection checks and is useful for optimizing large or complex applications.

To integrate Stripe with a custom checkout page, you can use Stripe's APIs and Stripe Elements. Elements provides pre-built UI components for securely collecting payment details. You’ll need to include Stripe.js in your checkout page and use Elements to create and manage payment forms. Once the payment information is collected, use Stripe's API to handle the payment processing and manage transactions. This approach allows for a fully customized checkout experience while maintaining PCI compliance.

You can customize your payment forms using Stripe Elements or Stripe Checkout. Stripe Elements provides a set of pre-built UI components that you can style to match your website's design. It offers flexibility while maintaining PCI compliance. Stripe Checkout is a pre-built, hosted payment page that can be customized with your branding and offers a streamlined payment experience.

Stripe Checkout is a pre-built, hosted payment page designed to simplify the payment process for customers. It provides a secure and user-friendly interface for handling payments, including support for various payment methods and currencies. Checkout is customizable with your branding and can be used for one-time payments or subscriptions. It handles the entire payment flow, from collecting payment details to processing the transaction, and integrates seamlessly with your Stripe account.

Stripe Elements and Stripe Checkout are two different tools for handling payments. Stripe Elements are pre-built UI components that you can integrate into your custom payment forms, giving you control over the design and functionality of your checkout page. Stripe Checkout, on the other hand, is a hosted, pre-built payment page provided by Stripe that offers a streamlined and user-friendly payment experience with less customization but quick setup. Both options handle payment processing securely and comply with PCI standards.