what is the programmatic parlance for this phenomenon?

Here is javascript code (jquery) for adding a row of images:

var tr = $('<tr>');
var td = '<td><img src="myimg.jpg"/></td>';
tr.append(td).append(td).append(td);
$('#mytable tbody tr:eq(0)').before(tr);
tr.empty(); //I really don't need this line...

Technically tr.empty() shouldn't have worked. It actually does the opposite of what I want. What is the techinical term for this behaviour - You've added tr to the DOM, but any jquery function calls to that object still works, where as you'd norm开发者_JAVA技巧ally not expect it to work i.e. make changes to the DOM?

I think you have a case of a shared mutable object. You are modifying the object in one place and are surprised to see the changes visible in another place. It's not technically wrong; it's just what happens when you have multiple references to an object that can be modified.

If there is a particular term for this other than 'object reference', I don't know what it is. I'd suggest that your expectation:

any jquery function calls to that object still works, where as you'd normally not expect it to work i.e. make changes to the DOM?

should be adjusted - for object variables, one should expect that whichever particular reference a change is made through, all references see the updated object.