SharePoint Curd Operation Using CSOM

Adding SharePoint 2013 SPList Item Using CSOM

string siteUrl = "http://MyServer/sites/MySiteCollection";

            ClientContext clientContext = new ClientContext(siteUrl);
            SP.List oList = clientContext.Web.Lists.GetByTitle("Announcements");

            ListItemCreationInformation itemCreateInfo = new ListItemCreationInformation();
            ListItem oListItem = oList.AddItem(itemCreateInfo);
            oListItem["Title"] = "My New Item!";
            oListItem["Body"] = "Hello World!";

            oListItem.Update();

            clientContext.ExecuteQuery(); 

Update SharePoint 2013 SPList Item Using CSOM

 string siteUrl = "http://MyServer/sites/MySiteCollection";

            ClientContext clientContext = new ClientContext(siteUrl);
            SP.List oList = clientContext.Web.Lists.GetByTitle("Announcements");
            ListItem oListItem = oList.Items.GetById(3);

            oListItem["Title"] = "My Updated Title.";

            oListItem.Update();

            clientContext.ExecuteQuery(); 

Delete SharePoint 2013 SPList Item Using CSOM

string siteUrl = "http://MyServer/sites/MySiteCollection";

            ClientContext clientContext = new ClientContext(siteUrl);
            SP.List oList = clientContext.Web.Lists.GetByTitle("Announcements");
            ListItem oListItem = oList.GetItemById(2);

            oListItem.DeleteObject();

            clientContext.ExecuteQuery();