JavaScript 中的Promise学习

<script type="text/javascript">
            new Promise(function(resolve, reject) {
                console.log(111);
                resolve(222);
            }).then(function(value) {

                console.log(value);
                return 333;
            }).then(function(value) {
                console.log(value);
                throw "An Error";
            }).catch(function(err) {
                console.log(err);
            }).finally(function(){
                console.log("End");
            });
        </script>