formatNumber = n => {

  n = n.toString()

  return n[1] ? n : '0' + n

}

// 时间格式化

formatTime = date => {

  const year = date.getFullYear()

  const month = date.getMonth() + 1

  const day = date.getDate()

  const hour = date.getHours()

  const minute = date.getMinutes()

  const second = date.getSeconds()

  return [year, month, day].map(formatNumber).join('-') + ' ' + [hour, minute, second].map(formatNumber).join(':')

}

使用：

formatTime(new Date())