what is PropTypes.symbol in react code example

Example 1: proptypes array of objects

MyComponent.propTypes = {
  items: PropTypes.arrayOf(
    PropTypes.shape({
      code: PropTypes.string,
      id: PropTypes.number,
    })
  ),
};

Example 2: react propthpes or

size: PropTypes.oneOfType([
  PropTypes.string,
  PropTypes.number
]),