form.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div id="sb">
    asdasda
    <p class="a">1</p>
    <p class="a" id="target" onclick="aa">2</p>
    <p class="a">3</p>
    <p class="a"> =3</p>
    <p id="q" class="a">4</p></div>
</body>
</html>
<script>

    function aa() {
        console.log(12);
    }


    let findIndex = Array.from(sb.childNodes).findIndex((value,index)=>{
        return value === q;
    });
     var ary=[]

    /*Array.from(sb.childNodes).forEach(function (item,index) {
        console.log(item);
        if( item.nodeType == 3 || item.nodeType == 1 ){
            if(item.nodeType == 3 && typeof(item.nodeValue) !== 'string'){
                console.log(12121);
                return
            }
            ary.push(item)
        }
    })*/


    console.log(findIndex);


</script>