OpenLayers interaction is not working when initializing in map object

Question

There is a problem to set interaction for the map object in OpenLayers. I've used this code but it's not working:

var osmLayer = new ol.layer.Tile({
    source: new ol.source.OSM()
});
var interaction = new ol.interaction.DragRotateAndZoom();
var center = ol.proj.transform([51.34, 35.65], 'EPSG:4326', 'EPSG:3857');

var view = new ol.View({
    center: center,
    zoom: 10
});

var map = new ol.Map({
    target: 'map',
    layers: [osmLayer],
    interactions: [interaction],     
    view: view
});

But when I use this template the interaction is just fine. what's wrong with first approach?

var map = new ol.Map({
    target: 'map',
    layers: [osmLayer],
    view: view
});
map.addInteraction(interaction);

Answer 1

You cannot simply pass an array with interactions, but you have to use ol.interaction.defaults().extend, like this:

var interaction = new ol.interaction.DragRotateAndZoom();

var map = new ol.Map({
    target: 'map',
    layers: [osmLayer],
    interactions: ol.interaction.defaults().extend([
        interaction
    ]),
    view: view
});

Then it will work without using map.addInteraction(interaction);