Requiring values

Let's make some adjustments to the preceding example. The component property specification requires specific types for values, but these are only checked if the property is passed to the component as a JSX attribute. For example, you could have completely omitted the myFunc property and it would have been validated. Thankfully, the PropTypes functions have a tool that lets you specify that a property must be provided, and it must have a specific type. Here's the modified component:

import React from "react";
import PropTypes from "prop-types";

export default function MyComponent({
  myString,
  myNumber,
  myBool,
  myFunc,
  myArray,
  myObject
}) {
  return (
    <section>
      <p>{myString}</p>
      <p>{myNumber}</p>
      <p>
        <input type="checkbox" defaultChecked={myBool} />
      </p>
      <p>{myFunc()}</p>
      <ul>
        {myArray.map(i => (
          <li key...