CODE EXAMPLE FOR JAVASCRIPT

PropTypes

import PropTypes from "prop-types";

MyComponent.propTypes = {
  name: PropTypes.string,
  id: PropTypes.number.isRequired,
  img: PropTypes.string
  grades: PropTypes.arrayOf(PropTypes.number),
  friends: PropTypes.arrayOf(
    PropTypes.shape({
      id: PropTypes.number,
    })
  ),
  list: PropTypes.arrayOf(PropTypes.any),
};

MyComponent.defaultProps = {
  img: "https://picsum.phones/200/300",
}