Car stalls at idle, takes time to restart, no codes

I was hoping someone here might be familiar with a problem I've been
having with my 2011 Hyundai Accent. My car randomly stalls when I
approach a stop or even while parked and idling. It happens on hot days and
even during relatively mild temperatures. Most of the time, it will restart
immediately. Sometimes, it takes awhile to restart. There are days when it
doesn't happen at all and days when it happens more than once. It doesn't
bring up any codes when I take it to a mechanic. I have had some
suggestions from friends but before I start replacing random parts, I would
love to hear any and all advice from those out there that might have a better
grasp of what's going on with my car. I appreciate taking the time to read this
and for any responses.