How to push additional fields to a javascript array from an oData result

I have a ramdom array in javascript

var dataModel = [];

I've queried an oData url and I want to fill the result in my dataModel [] array. And, for each item I want to add additional fields

odataMod.read(
        "/",
        null, [],
        true,
        function (oData, oResponse) {
            var data = oData.results;
        data.forEach(function (item) {
            //Add the object 
            dataModel.push(item);
            //I want to add additional fields to every object in data 
            dataModel.push(item.ObjectType = "Chevron");
            dataModel.push(item.HierarchyNodeLevel = 0);
            dataModel.push(item.IsCriticalPath = false);
            dataModel.push(item.IsProjectMilestone = false);
            dataModel.push(item.DrillDownState = "expanded");
            dataModel.push(item.Magnitude = 5);

…

Note : the ObjectType , DrillDownState , Magnitude (etc…) are the fields that I want to add with their values Chevron, 0, false (etc…)

Below is a screenshot of the current result :

But I want to add the additional properties inside each item and not outside , what I am doing wrong? In other word, I want the additional fields to be inside the metadata

Below is a sc of where I would like to add the items :

#javascript #arrays