javascript - Identity selectors in jQuery returning arrays -

suppose have div tag this:

<div id="group-dialog" class="modal-dialog"> 

now want grab jquery object (in case can run .dialog()).

when try this:

var gdialog = $('#group-dialog'); 

i array (!!).

why getting array? isn't point of having id attribute there's one? can see getting multiple p's or .my-css-thing ...

next question:

i have array 1 object in want access jquery object.

when this:

$(gdialog[0]) 

and pull in f12, still have array!! thought de-referenced array picking first element.

this doesn't seem either:

var gdialog = $('#group-dialog:first'); 

this basic, run problem lot. seems used lot simpler!

what best way access dom element jquery object?

answer 1
jquery selectors return arrays.
selection id attribute particular use case , ideally result should unique. however, there nothing preventing having duplicated ids in html document (although bad practice).

answer 2
following code first element dom object:

var gdialog = $('#group-dialog')[0]; 

note: may want check size of return array first.

as far know, there no way transform dom element jquery object. standard use case directly used $('#group-dialog') , asume found , unique.