前端如何判断浏览器刷新还是关闭

// 监听浏览器关闭事件
const arrTTT = [
  '/main/securityOperationScreen',
  '/main/threat-situation-screen',
  '/main/RiskSituationScreen',
  '/main/AssetSituationScreen',
  '/main/securityBusinessDevelopment',
  '/main/industrySupervisionScreen',
  '/main/adminSituationScreen',
  '/main/IndustryRegulatorySecuritySituation',
  '/main/comprehensiveSituation'
]
let _beforeUnload_time = 0
let _gap_time = 0
window.addEventListener('beforeunload', e => {
  _beforeUnload_time = new Date().getTime()
})
window.addEventListener('unload', e => {
  _gap_time = new Date().getTime() - _beforeUnload_time //获取时间差
  //判断页面是关闭还是刷新
  let str = window.location.href
  let arr = str.split('#')
  if (!arrTTT.includes(arr[1])) {
    if (_gap_time < 3) {
      libs.clearCache()
    }
  }
})

这里对一些系统中需要弹出新页面的做了判断，避免关闭这些弹出页面导致清空缓存