Convert the pseudo array returned by childNodes into a true array

One , reason

What we got childNodes The return is an array like object , Print it out and you will find . There is no common method of array on its prototype ：

console.log("+++++",el.childNodes)

You'll get ：

Two , Convert a pseudo array to a true array

const newArr=[].slice.call(el.childNodes)
console.log("====",newArr)

What is called is actually Array.protype Upper slice Method , there call No parameters passed in , So cut from the first item to the last item . Do not change the original pseudo array .
The true array returned after this , Array methods can be used normally .