Exit android app on back pressed

Question

I am building an Android App. How to exit an Android App when back is pressed. Android version is 2.3.3 and above. The Android App goes to previous activity which i don\'t want.

Answer 1

Kotlin:

 override fun onBackPressed() {
        val exitIntent = Intent(Intent.ACTION_MAIN)
        exitIntent.addCategory(Intent.CATEGORY_HOME)
        exitIntent.flags = Intent.FLAG_ACTIVITY_CLEAR_TOP
        startActivity(exitIntent)
    }

Other codes have problems, some does not work and some needs API classification.