<button onclick="CreateListItem();" type="button">Click me</button>

 

<script src="https://code.jquery.com/jquery-2.2.4.js" type="text/javascript"></script>

<script type="text/javascript" src="/_layouts/15/sp.runtime.js"></script>

<script type="text/javascript" src="/_layouts/15/sp.js"></script>

 

<script type="text/javascript">

    function CreateListItem() {       

        try

        {            

            // var clientContext = new SP.ClientContext("http://MyServer/sites/SiteCollection");

            var clientContext = new SP.ClientContext();

 

            var oWeb = clientContext.get_web();

 

            // Specify list title here

            var oList = oWeb.get_lists().getByTitle("Employee");

 

            // Get Item using CAML Query

            var camlQuery = new SP.CamlQuery();

 

            // New "ListItemCreationInformation" Object

 

 

            // Set value for each column here

            //oListItem.set_item('Title', 'New item value');

            //oListItem.set_item('Notes', 'This is dummy data');

            for (var i = 0; i < 5000; i++) {

                var oListItemCreationInformation = new SP.ListItemCreationInformation();

                var item = oList.addItem(oListItemCreationInformation);

                item.set_item("Name", "Test Title " + i);

                if (i < 20) {

                    item.set_item("Age", 25);

                    item.set_item("Salary", 25000 + i);

                }

                else if (i > 20 && i < 100) {

                    item.set_item("Age", 30);

                    item.set_item("Salary", 25000 + i);

                }

                else {

                    item.set_item("Age", 35);

                    item.set_item("Salary", 25000 + i);

                }

                item.set_item("Office", "Office  " + i);

                item.set_item("Position", "Position  " + i);

 

                item.set_item("Title", "Title  " + i);

                item["StartDate"] = Date.now();

                item.update(); 

 

                clientContext.load(item);

 

                // Execute the query to the server.

                clientContext.executeQueryAsync(onsuccess, onfailed);

            }

        }

        catch (ex) {

            console.log(ex.message);

        }

    }

 

    function onsuccess() {

      //  console.log("Success");

    }

 

    function onfailed(sender, args) {

        console.log('Failed' + args.get_message() + '\n' + args.get_stackTrace());

    }

</script>