stdClass Object
(
    [CountyId] => 3
    [Name] => Alba
    [Abbreviation] => AB
)
stdClass Object
(
    [CountyId] => 4
    [Name] => Arad
    [Abbreviation] => AR
)
stdClass Object
(
    [CountyId] => 5
    [Name] => Arges
    [Abbreviation] => AG
)
I want to convert this collection of stdClass Object into an array that contains only the CountyId, such as
[CountyId[0] => 3, CountyId[1] => 4, CountyId[2] => 5,...]. 
Anyone can help me ?
 
     
    