var clientContext = new SP.ClientContext("http://xxxx/subsite/"); // to bechanged
var dokumentname = "";// name of the folder
    
var oList = clientContext.get_web().get_lists().getByTitle("library name");// to be changed
var itemCreateInfo = new SP.ListItemCreationInformation();
itemCreateInfo.set_underlyingObjectType(SP.FileSystemObjectType.folder);
itemCreateInfo.set_leafName(dokumentname);
this.oListItem = oList.addItem(itemCreateInfo);
this.oListItem.set_item("Title", dokumentname);
this.oListItem.EnableFolderCreation = true;
this.oListItem.update();
clientContext.load(this.oListItem);
clientContext.executeQueryAsync(
        Function.createDelegate(this, onFolderCreationSuccess),
        Function.createDelegate(this, onFolderCreationFail)
    );


function onFolderCreationSuccess(){
    alert("folder created sucessfully");
    uploadfiletrial();
}
function onFolderCreationFail(){
    alert("folder not created");
}



    var element = document.getElementById("abcd");// id of the data fetcher in html
    
    
function  uploadfiletrial(){
    var uploadcount = 0;
    var objektcount = element.files.length-1;
    uploadabc(uploadcount);
    function uploadabc(uploadcount){
        if(uploadcount<= objektcount)
         {  
            var element = document.getElementById("abcd");
            var filename = element.files.item(uploadcount).name;  

            var file = document.getElementById("abcd").files[uploadcount];
            console.log(filename+"|"+file);
            uploadFileSync("xxx"+dokumentname, filename, file);// replace xx with location to library
            uploadcount++;
            alert(uploadcount);
            uploadabc(uploadcount);
         }
        }
    }
//Upload file synchronously
function uploadFileSync(folderUrl, filename, file)
{
    var reader = new FileReader();
    reader.onloadend = function(evt)
    {
        if (evt.target.readyState == FileReader.DONE)
        {
            var buffer = evt.target.result;
            var completeUrl = "http://xxx/xxx/xxx/_api/web/GetFolderByServerRelativeUrl('"+folderUrl+"')/Files/add(url='" + filename + "',overwrite=true)"; // replace xxx with the lcoation of the library
           $.ajax({
                url: completeUrl,
                type: "POST",
                data: buffer,
                processData: false,
                headers: {
                    "accept": "application/json;odata=verbose",
                    "X-RequestDigest": $("#__REQUESTDIGEST").val(),
                    "content-length": buffer.byteLength
                },
                complete: function (data) {
                    console.log(data.responseJSON.d.ServerRelativeUrl);
                },
                error: function (err) {
                    console.log(err);
                }
            });

       }
    };
    reader.readAsArrayBuffer(file);
}