I was investigated for shoplifting but released with a warning without charge. Dose it mean my charge is dismissed? Do I need to declare this when seeking employment in future.

If you weren't charged or convicted of anything, then you don't need to reveal that this sort of thing happened. However, what do you mean that you were released with a warning? Were you issued some kind of ticket? Did the police actually arrest you?

Call the police and ask them if you were charged. If there is any more that you have to do. Because you don't want to get in any more trouble like not showing up to court Or not paying a fine.
PS you are lucky that you got a warning. Hope this will help u stop. NOT WORTH IT MAN

Investigated does not even mean charged, if you were charged you would have either received a ticket or been arrested and had charges read in court. Investigated means investigated, they had you as a suspect but at this time did not have enough evidence to charge you.

So your charge can not be dismissed, if there was never a charge to start with. If you were charged, then you would have had to have the DA drop the charges.

Also in employment applicatoins, they ask if you had ever been convicted, they do not ask if you had ever been arrested or charged. ** at least most of them

Chuck is soooo right he has that way of simplifying things. Call see where you stand.
And you are OK with you application right now. Even a police check

You don't have anything to worry about as you did not go to court and were not convicted of shoplifting. Relax. It is not on the books anywhere. You can forget about it as it didn't happen.