JavaScrit 如何区分单击双击事件

<button onclick="fnc()" ondblclick="fncDb()">click</button>

function fnc() {
  clearTimeout(fnc.clickTimeId)
  fnc.clickTimeId = setTimeout(function() {
    console.log('click')
  }, 500)
}
function fncDb() {
  clearTimeout(fnc.clickTimeId)
  console.log('db click')
}