JavaScript - How to make an array that contains objects by reference?

Question

Hi, I'm using JavaScript Mapping Library - OpenLayer to create a markers overlay. I want to control the markers dynamically: add new ones and remove existing markers from the layer.

the way to add a new marker to the layer is by the command:

markers.addMarker(new OpenLayers.Marker(new OpenLayers.LonLat(0,0),icon));

as you can see, the initialization parameters contain only coordinates and icon image, not id, even not as an optional parameter.

in order to control the markers I want to create 2 dimensional array, that contain markers array by reference and ID array.

then, when I want to remove a marker from the layer, the command will be simply:

markers.removeMarker(ArrayMarkers[i]);

How do I push an element to JavaScript array by reference?

How can I run on ArrayMarkers elements by reference?

Answer 1

Try:

var ArrayMarkers = [];
var myMarker = new OpenLayers.Marker(new OpenLayers.LonLat(0,0),icon);
markers.addMarker(myMarker);
ArrayMarkers.push(myMarker);

Basically, JavasScript generally uses references to pass objects around. You're already passing a reference in to the library. You can use the same technique.

Answer 2

In JavaScript, you can't chose to push an variable by value of by reference... this is done automatically depending on the type of the variable.

I guess your markers are Objects. So they will be pushed in the array by reference. The ids are String, they will be pushed by value.