getID for button returns -1
<pre><code>public class Test extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Button b = new Button(this);
        String id = Integer.toString(b.getId());
        Toast.makeText(getApplicationContext(), id, 1).show();
    }
}
</code></pre>

<p>Why does it return -1?</p>
