php - how to get the '0' entry in object -

i have following object:

stdclass object ( [0] => stdclass object ( [img_id] => 56 [img_name] => 5c9eeb51930ebe222ab26895dab7c348.png ) ) 

it being dumped variable called $image_names. trying entry [0].

i have tried:

$image_names->0 error: syntax error, unexpected t_lnumber

i tried $image_names[0]. realize should not work, thought give try. not return error. but, not return data.

in object structure, how object associated key [0]?

same always.

$image_names->{'0'}