how to set proptype as not required code example

Example 1: proptypes oneof

import PropTypes from 'prop-types';

MyComponent.propTypes = {
  // You can declare that a prop is a specific JS type. By default, these
  // are all optional.
  optionalArray: PropTypes.array,
  optionalBool: PropTypes.bool,
  optionalFunc: PropTypes.func,
  optionalNumber: PropTypes.number,
  optionalObject: PropTypes.object,
  optionalString: PropTypes.string,
  optionalSymbol: PropTypes.symbol,

  // An object that could be one of many types
  optionalUnion: PropTypes.oneOfType([
    PropTypes.string,
    PropTypes.number,
    PropTypes.instanceOf(Message)
  ])
};

Example 2: react proptypes example

// proptypes using class component
Detaljer.PropTypes = {
  detaljer: PropTypes.string.isRequired,
  feilkode: PropTypes.string,
  removeEvent: PropTypes.string.isRequired
};

// proptypes using function component
Detaljer.propTypes = {
  detaljer: PropTypes.string.isRequired,
  feilkode: PropTypes.string,
  removeEvent: PropTypes.string.isRequired
};