React best Practice default props example

ModalButton.js

import React, { Component } from "react";
import { Button } from "react-bootstrap";
import PropTypes from 'prop-types'

class ModalButton extends Component {
  render() {
    return <Button variant={this.props.variant}>{this.props.children}</Button>;
  }
}

ModalButton.defaultProps = {
  variant: "outline-info",
  children: "Info"
};

ModalButton.propTypes = {
  variant: PropTypes.string,
  children: PropTypes.string
}

ReactDOM.render(<ModalButton />, document.getElementById('root'));