demo.html

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div class="aa">aaaa</div>
    <script>
        // let aa = document.querySelector('.aa');
        // aa.addEventListener('touch')
        async function alg() {
            return new Promise((r, e) => {
                e('ERR')
            })
        }
        async function bbb() {
            let bb = await alg().catch(err => {
                return { catch: true }
            })
            setTimeout(() => {
                console.log(bb);
            }, 500);
        }
        bbb();
        console.log([11, 22, 33].concat(33, 22, 11));
    </script>
</body>

</html>