React.PropTypes.number控制台报错说number是undefined

Question

组件里  BodyIndex.propTypes = {    usernum: React.PropTypes.number  };控制台报错显示的是：Cannot read property 'number' of undefined不知道错在哪里，react小白请大神帮忙解决

Answer 1

BodyIndex.propTypes = {

    usernum:  PropTypes.number

  };