相关疑难解决方法(0)

鉴于此组件:

import React from 'react'
import ReactDOM from 'react-dom'
import PropTypes from 'prop-types'

const NewGoalInput = props => {
  return (
    <input type="text" onKeyUp={handleKeyUp}/>
  )
}

const handleKeyUp = (e) => {
  if (e.key === "Enter") {
    // TODO Add goal
  }
}

export default NewGoalInput

如何在不使用extends React.Component语法的情况下添加构造函数来定义状态？