Adding data to list in a Batch in SharePoint

SharePoint provide a functionality to perform CRUD operation in "bulk" with SPWeb's Batch Process methods. Below is the sample to ADD items in bulk.

//Hard Coded e.g. This I have just describe to learn the CAML query thoroughly.
<ows:Batch OnError="Return">1</ows:Batch>//1=itemID.
<Method ID="1">//1=itemID. Note - itemID is in double quotes.
    <SetList>2222-22222222-2222</SetList>//ListID
    <SetVar Name="Cmd">Save</SetVar>
    <SetVar Name="ID">1</SetVar>//1=itemID
    <SetVar Name="urn:schemas-microsoft-com:office:office#Title">Title 1</SetVar>
</Method>

//Dynamic Code e.g.
<ows:Batch OnError="Return">{0}</ows:Batch>//1=itemID.
<Method ID=\"{0}\">//1=itemID. Note - itemID is in double quotes.
    <SetList>{1}</SetList>//ListID
    <SetVar Name="Cmd">Save</SetVar>//Use Delete keyword to delete item, Save keyword to update item
    <SetVar Name="ID">{2}</SetVar>//1=itemID
    <SetVar Name="urn:schemas-microsoft-com:office:office#Title">{3}</SetVar>
</Method>

---------------------------------------------------------------------------------------------------------
Real time application e.g. with bulk updates.

               
                using (SPSite site = new SPSite(gstrURL))
                {
                    using (SPWeb web = site.OpenWeb())
                    {
                        SPList listBatch = web.Lists["BatchTest"];
                        string lstrBatchFormat = string.Empty, lstrMethodFormat = string.Empty;
                        StringBuilder methodBuilder = new StringBuilder();
                       
                        lstrBatchFormat = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" +
                              "<ows:Batch OnError=\"Return\">{0}</ows:Batch>";

                        lstrMethodFormat ="<Method><SetList>{1}</SetList>" +
                                "<SetVar Name=\"ID\">New</SetVar>" +
                                "<SetVar Name=\"Cmd\">Save</SetVar>" +
                                "<SetVar Name=\"urn:schemas-microsoft-com:office:office#Title\">" +
                                "{2}</SetVar>" +
                                 "<SetVar Name=\"urn:schemas-microsoft-com:office:office#aaa\">" +
                                "{3}</SetVar>" +
                                "</Method>";

                        for (int i = 0; i < listBatch.Items.Count; i++)
                        {
                            SPListItem item =listBatch.Items[i];
                            methodBuilder.AppendFormat(lstrMethodFormat,  listBatch.Items.Count++, listBatch.ID.ToString(), "Title-" + i, "aaa-" + i);
                        }

                        string lstrBulkBatch = string.Format(lstrBatchFormat,methodBuilder);
                        string lstrResult = web.ProcessBatchData(lstrBulkBatch);

                    }
                }

MSDN Reference:
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