The happy couple left an L.A. restaurant together Friday night ... and, check out the smiles on their faces -- clearly, these two lovebirds are crazy about one another.

The two dressed casually for their evening out ... Jennifer in a comfy blue sweater while John's rocking a t-shirt and flannel -- smiles galore while the valet runs to get their car.

Of course, we knew the pair were still crazy about each other ... remember, we recently told you Garner had no plans to get back together with Ben Affleck after Jennifer Lopez filed to divorce him earlier this week.

Sources close to the situation told us they weren't on a break as some had reported, and their relationship hadn't changed one bit despite the divorce.

We're told BA and JG are rocking the co-parenting game ... and, that's really all the closeness they have -- with no desire to try again after their shocking divorce became final in 2018.

J Lo filed for divorce citing irreconcilable differences this week ... and, there are a ton of guys who are the betting favorites to land with the triple-threat -- including Eminem who's currently out in front.