demo1.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
        let shadowCopy = (obj) => {
            if(typeof obj !== 'object' || obj === null) return;
            let result = obj instanceof Array ? [] : {};
            for(let key in obj){
                result[key] = obj[key]
            }
            return result;
        }


        let deepCopy = (obj) => {
            if(typeof obj !== 'object' || obj === null) return;
            let result = obj instanceof Array ? [] : {};
            for(let key in obj){
                if(obj.hasOwnProperty(key)){
                    if(typeof obj[key] == 'object' && obj !== null ){
                        result[key] =  deepCopy(obj[key])
                    }else{
                        result[key] = obj[key]
                    }
                }   
                
            }
        }
    
    </script>
</body>
</html>