Sharepoint - Results from REST API Query field undefined

Question

I'm using REST/JS calls to populate certain fields from a certain list item. I'm having troubles grabbing some of the fields as they are showing up as undefined when displaying results. I have noticed though, the fields that are showing up as undefined are type: Lookup, Person or Group, or Choice. Types that are showing up are Single line of text, Date and Time, and Number. I have looked through article after article but have not been able to figure it out. Here is a snip it of some of the code I'm talking about:

$(function() {

    $.ajax({
            url: "__URL__/_api/lists/getbytitle('Master%20Project%20List')/items?&$filter=Number eq '" + projectId + "'",
            headers: {"Accept": "application/json;odata=verbose"}, 
            type: "GET", 
            cache: false,
            async: false,      

    }).success(function (data) {
        $.each(data.d.results, function(key, value) {

            //Project Title
            console.log("TEST TITLE - " + value.Title);
            Title = "*" + value.Title; 

            //Project Divison
            console.log("TEST DIVISION - " + value.Div);
            division = "*" + value.Div;

        }); 
    });
}); 

Here is a similar post: https://sharepoint.stackexchange.com/questions/147909/some-fields-undefined-when-display-results-from-rest-query

Answer 1

You may need to explicitly request the desired field values using the $select and $expand options.

The $expand option specificies which projected fields from a joined list are returned.

Consider the following excerpt from SharePoint 2013 - Understanding the SharePoint 2013 REST Interface by Jim Crowley and Ricky Kirkham:

When a SharePoint list has a lookup field to another list, this effectively serves as a join of the two lists. You can use the $expand option to return projected fields from the joined list. For example, if the Books list has a PublishedBy field that looks up to the Name field of a Publisher list, you can return those names with this URL:

 _api/web/lists/getByTitle( 'Books')/items?$select=Title,PublishedBy/Name&$expand=PublishedBy 

Notice that you reference the column in the foreign list by using the syntax lookup_column_display_name/foreign_column_name , not foreign_list_name/foreign_column_name . It's also important to note that you can't select a lookup field name without also expanding it.

For more examples, see the answers given to this question on the SharePoint Stack Exchange site.