Adding Menu to the activity, customising the action bar

Android-CustomiseActionBar-Menu.java

    //  For Creating a menu in android, we need to add a new file. and we need to customise
    //  MainActivity.java file.
    //  The new file is a xml layout file which only gives the layout for our menu
    //  We created a folder in res as menu an inside that created a menu resource file.
    //  We customise the xml file and added items for the menu.
    <menu xmlns:android="http://schemas.android.com/apk/res/android">
        <item
            android:id="@+id/settings"
            android:title="Setting"/>
        <item
            android:id="@+id/help"
            android:title="Help"/>
    </menu>

    //  We should add this override.
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        //  what we mainly want to do is linking this options Menu with the xml file that
        //  we just created.
        MenuInflater menuInflater = getMenuInflater();
        menuInflater.inflate(R.menu.main_menu, menu);

        return super.onCreateOptionsMenu(menu);
    }

    //  now the menu will appear. but it will do nothing. so we add
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        super.onOptionsItemSelected(item);
        //  we are going to check which item is sellected. we use a switch.
        //  switch is like a big if else statement.
        switch (item.getItemId()) {
            case R.id.settings:
                Log.i("Lord-Menu", "Settings");
                return true;
            case R.id.help:
                Log.i("Lord-Menu", "Help");
                return true;
            default:
                return false;
        }
    }