swift – Learn how to deal with GSJ02 and WGS84 coordinate system in ios MKMapview?

As I’ve carried out evaluation, i obtained to know china utilizing Gcj02 coordinate system.
so I’ve some douts on under situations

So in my ios app I’m utilizing MKMapview and displaying some location which I get in WGS84 format

1. If the situation which l get in response is for mainland China and we proven because it as for outdoor china person will it present right location or not? Or that can also be must convert in Gcj02?
2. In identical case what is going to occur if person can also be in mainland China(MKMapview will present as AMap) and placement can also be in mainland land china? Do we have to convert?
3. If person is outdoors china and placement can also be outdoors china then he can see right location.
4. However when person in china(MKMapview will present as AMap) and placement is outdoors china? Will that location displayed appropriately?

As there are some converter lessons accessible for wgs to gcj or vice versa

As per above situations if I’ve to make use of each GCJ to WGS and WGS to GCJ, how will I get know location is wherein format?

Thanks prematurely in your assist!!!