React by value, type, and default value of the verification value

const ele = <Ff const = { 'ha'} index = {55}> </ Ff>
let box = document.querySelector('#app')
// console.log(box)
// mount
render (he, box)

　　

import React,{Component} from 'react'
import PropTypes from 'prop-types'

export default  class ClickS extends React.Component {
  constructor (props) {
    super(props)
    this.state= {
      msg: '123'
    }
    console.log(this.props)
  }
  render () {
    return <div>
  <h2>{this.state.msg}------{this.props.index}---{this.props.const}---{this.props.name}</h2>

    </div>
  }

ClickS.propTypes = {
  const: PropTypes.string.isRequired, // denotes must pass, whose type is String 
　index: PropTypes.number 
}

　　It is a proven method // func representation

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 If no value is passed, to which a default value

ClickS.defaultProps = {
  name: 'John Doe'
}