var clientContext = new SP.ClientContext.get_current(); //if the page and the list are in same site.If list is in different site then use relative url instead of get_current
var oList = clientContext.get_web().get_lists().getByTitle(‘Contacts‘);
var itemCreateInfo = new SP.ListItemCreationInformation();
var oListItem = oList.addItem(itemCreateInfo);

var contactTypes = null;

$.each(contact.contactTypes, function (index, contactType) {
    if (index != 0)
        contactTypes += ‘;#‘ + contactType.id + ‘;#‘ + contactType.title;
    else
        contactTypes =  contactType.id + ‘;#‘ + contactType.title;
});

// other set_item statements omitted for brevity
oListItem.set_item(‘ContactType‘, contactTypes);

oListItem.update();

clientContext.executeQueryAsync(
    // success return
    function () {
        var success = true;
    },
    // failure return
    function (sender, args) {
        window.alert(‘Request to create contact failed. ‘ + args.get_message() +
                ‘\n‘ + args.get_stackTrace());
    })
 

SharePoint 客戶端對象模型 多選查閱項賦值