类型不匹配：推断类型为 String 但预期为 Int，Kotlin

Question

Task:app:compileDebugKotlin FAILED

Type mismatch: inferred type is String but Int was expected

Answer 1

What is the problem? The IDE itself tells you, an Int was expected but you are passing a String.

To get values ​​from resources, for example, strings, themes, etc... you need to pass an Int or id of the resource, which is obtained by doing

R.id.your_resource

Answer 2

So looking at your code:

val InterstitialId = dataSnapshot.child("interstitial_id").value.toString()

This line will return a string when you call the .toString method, 2 lines below you are passing this variable to a .getString and according to the documentation getString() expects an Int not a String.