DemoActivity.kt

class DemoActivity : AppCompatActivity(){
       
       override fun onCreate(savedInstanceState: Bundle?) {
              super.onCreate(savedInstanceState)
              setContentView(R.layout.activity_demo)
              //now we creating adapter and passing in a lambda method
              var demoAdapter = DemoAdapter{ item -> doClick(item) }
           }
       
           //creating method to make it look simpler
           fun doClick(item:Any) {
               //do things related to activity
           }
}