To be an app developer which languages I have to learn?

Question

I already completed #c and learning Java

Answer 1

Java is popular for android app development where swift & objective c is popular on ios app development , 2019 to present new technology are getting popular like kotlin on Android React native for cross platform app development with JavaScript or Google popular flutter.

https://www.sololearn.com/discuss/358950/?ref=app
https://www.sololearn.com/discuss/1556225/?ref=app
https://www.sololearn.com/discuss/347474/?ref=app
https://www.sololearn.com/discuss/236235/?ref=app
https://www.sololearn.com/discuss/281722/?ref=app