qmining-page/src/components/Subject.js

import React, { PureComponent } from 'react'

import Question from './Question.js'

class Subject extends PureComponent {
  render () {
    const { subj } = this.props

    if (subj) {
      return (
        <div >
          {subj.Questions.map((question, i) => {
            return (
              <Question
                key={i}
                question={question}
              />
            )
          })}
        </div>
      )
    } else {
      return (
        <div />
      )
    }
  }
}

export default Subject