//Without extension
inputET.addTextChangedListener(object:  TextWatcher {
    override fun afterTextChanged(s: Editable?) {

    }

    override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {

    }

    override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {

    }
})

//With extension
inputET.afterTextChanged {

}

//Extension function
fun EditText.afterTextChanged(afterTextChanged: (String) -> Unit) {
    this.addTextChangedListener(object : TextWatcher {
        override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
        }

        override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
        }

        override fun afterTextChanged(editable: Editable?) {
            afterTextChanged.invoke(editable.toString())
        }
    })
}