onCreateOptionsMenu.java

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // COMPLETED (9) Within onCreateOptionsMenu, use getMenuInflater().inflate to inflate the menu
    getMenuInflater().inflate(R.menu.main, menu);
    // COMPLETED (10) Return true to display your menu
    return true;
}

onOptionsItemSelected.java

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int itemThatWasClickedId = item.getItemId();
    if (itemThatWasClickedId == R.id.action_search) {
        Context context = MainActivity.this;
        String textToShow = "Search clicked";
        Toast.makeText(context, textToShow, Toast.LENGTH_SHORT).show();
        return true;
    }
    return super.onOptionsItemSelected(item);
}