ACTIVITY_MAIN.XML:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context=".MainActivity">
 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="ACTIVITY LIFE CYCLE DEMO"
 app:layout_constraintBottom_toBottomOf="parent"
 app:layout_constraintEnd_toEndOf="parent"
 app:layout_constraintHorizontal_bias="0.5"
 app:layout_constraintStart_toStartOf="parent"
 app:layout_constraintTop_toTopOf="parent"
 app:layout_constraintVertical_bias="0.5" />
</androidx.constraintlayout.widget.ConstraintLayout>
MAINACTIVITY.kt
package com.example.myapp_activitylifecyclemethods
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
class MainActivity : AppCompatActivity() {
 override fun onCreate(savedInstanceState: Bundle?) {
 super.onCreate(savedInstanceState)
 setContentView(R.layout.activity_main)
 Toast.makeText(applicationContext,"ONCREATE() 
CALLED",Toast.LENGTH_SHORT).show()
 }
 override fun onStart() {
 super.onStart()
 Toast.makeText(applicationContext,"ONSTART() 
CALLED",Toast.LENGTH_SHORT).show()
 }
 override fun onRestart() {
 super.onRestart()
 Toast.makeText(applicationContext,"ONRESTART() 
CALLED",Toast.LENGTH_SHORT).show()
 }
 override fun onResume() {
 super.onResume()
 Toast.makeText(applicationContext,"ONRESUME() 
CALLED",Toast.LENGTH_SHORT).show()
 }
 override fun onPause() {
 super.onPause()
 Toast.makeText(applicationContext,"ONPAUSE() 
CALLED",Toast.LENGTH_SHORT).show()
 }
 override fun onStop() {
 super.onStop()
 Toast.makeText(applicationContext,"ONSTOP() 
CALLED",Toast.LENGTH_SHORT).show()
 }
 override fun onDestroy() {
 super.onDestroy()
 Toast.makeText(applicationContext,"ONDESTROY() 
CALLED",Toast.LENGTH_SHORT).show()
 }
}