When we start new activity into kotlin why we put .java in intent instead of .kt

Question

As per kotlin doc we start new activity with following syntax

startActivity(Intent(this@MainActivity, NextActivity::class.java))

its kotlin

Answer 1

Because NextActivity::class gives you KClass<NextActivity>, and KClass has a method/extension property called java which gives you the java.lang.Class<NextActivity> for the given class.

You can even check out the source-code for that java property.