Get all items from a list without referring to them one by one

Question

I would like to know if there is a way to get all items without referring one by one like I have done in my code? This code returns nothing.

function onS() {
    var listString = "";
     var Enum = listItems.getEnumerator();
       while (Enum.moveNext()) {
     var currentItem = Enum.get_current();
    var data = currentItem.get_fieldValues();
    listString += currentItem.Title;
    }
    $("#items").html(listString);
}

Answer 1

if you want to get the JSON response of all field values use get_fieldValues() method

var currentItem = Enum.get_current();
 var data = currentItem.get_fieldValues();

it returns the keyvalue pair JSON data like

{'Title':'Title Value',
 'ID':'ID value',
 'ColumnInternaName':'ColumnValue',
  .....
  .....}

you can get the title by

data.Title

Id by

data.ID

etc...

if you load items using 'Include' like

context.load(listItems,'Include(Title,ID)')

Then the JSON only contains the data of Title and ID

Answer 2

I am mostly using REST to get all items from a list like the code below:

<script type="text/javascript">

                $(document).ready(function() {    

                    // Rest Call
                    var requestUri = "/_api/lists/getbytitle('News')/items";

                        $.ajax({
                            url: requestUri,
                            type: "GET",
                            headers: { "ACCEPT": "application/json;odata=verbose" },
                            success: function (data) {
                                $.each(data.d.results, function (i, item){
                                    var title = item.Title;
                                    var description = item.Description;
                                    var pictureURLDesc = item.PictureURL.Description;
                                    var pictureURL = item.PictureURL.Url;   
                                    var linkDesc = item.Link.Description;
                                    var linkURL = item.Link.Url;    
                                    var currentItemID = item.ID;                

                                    try 
                                    {   
                                        // Slice description
                                        if (description.length > 102){
                                            llength = description.slice(0, 102) + " ...";
                                        }
                                        else {
                                            llength = description;
                                        }
                                    } 
                                    catch ( err ) 
                                    { 
                                        alert( err ); 
                                    }               

                                    // Check News item   
                                    alert("Item Nr: " + currentItemID + "Title: " + title + "Description: " + llength);                 
                                })
                            },
                            error: function () {
                                alert("Error getting items");
                            }                     
                        });   
});                              
</script>