DOUBLE PRESS BACK BUTTON TO EXIT APP || KOTLIN ANDROID STUDIO

Click here for video guidance 

STEP 1: CREATE A NEW PROJECT WITH EMPTY ACTIVITY

STEP 2: OPEN MainActivity.kt FILE.

STEP 3: PASTE FOLLOWING CODE IN MainActivity.kt FILE

private var doubleBackToExitPressedOnce = false
override fun onBackPressed() {
    if (doubleBackToExitPressedOnce) {
        super.onBackPressed()
        return
    }

    this.doubleBackToExitPressedOnce = true
    Toast.makeText(this, "Please click BACK again to exit", Toast.LENGTH_SHORT).show()

    Handler(Looper.getMainLooper()).postDelayed(Runnable { doubleBackToExitPressedOnce = false }, 2000)
}

STEP 3: IF ANY RED MARKS OCCUR, CLICK ON THAT AND PRESS THE KEY ALT+ENTER.

STEP 4: DONE! NOW LAUNCH THE APP.

tags : Android studio tutorial, double press back button to exit app, kotlin , java,