This sample shows how to use kotlin .apply() based on fragment instantiating example. There are 4 examples: first in Java, second in Kotlin without apply(), third in Kotlin with one apply(), and last in Kotlin with two apply().

ApplyExample.kt

// Java
public static DetailsFragment newInstance(int id) {
        Bundle arguments = new Bundle();
        arguments.putInt("id", id);
        DetailsFragment fragment = new DetailsFragment();
        fragment.setArguments(arguments);
        return fragment;
    }


// Kotlin without apply()
companion object {
    fun newInstance(id: Int): DetailsFragment {
        val arguments = Bundle()
        arguments.putInt("id", id)
        val fragment = DetailsFragment()
        fragment.setArguments(arguments)
        return fragment
    }
}


// Kotlin with one apply()
companion object {
    fun newInstance(id: Int): DetailsFragment = DetailsFragment().apply {
        val arguments = Bundle()
        arguments.putInt("id", id)
        setArguments(arguments)
    }
}

// Kotlin with two apply()
companion object {
    fun newInstance(id: Int): DetailsFragment = DetailsFragment().apply {
        arguments = Bundle().apply { arguments.putInt("id", id) }
    }
}