How can I add a ViewPager to a class?

Question

Android

Good afternoon. I'm starting to learn programming for android. I found a tutorial where you can change screens with a swipe (left-right). When I got to the declaration of ViewPager in MainActivity, I ran into an error (Expecting member declaration).
Here is the code:

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity

class IntroActivity : AppCompatActivity() {

    private ViewPager screenPager;


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_intro)

        //setup ViewPager
        screenPager = findViewById(R.id.screen_viewpager)
    }
}

Here is this line

private ViewPager screenPager;

and doesn't work.
The only thing is that the project was created in Kotlin. Maybe because of this?
Android studio 3.6.1

Answer 1

This is a kotlin class. You cannot declare a variable in it in the syntax of java.
You need to write the whole class in one language