how to add icon to elevated button in flutter code example

Example 1: flutter change the icon of icon button on pressed

bool selected = true;

//...

Widget build(BuildContext context) {
	return Scaffold(
    	body: Center(
          child: IconButton(
              icon: Icon( selected ? Icons.celebration : Icons.title),
              onPressed: () {
                setState(() {
                  selected = !selected;
                });
              },
          ), //IconButton
   		), //Center
    ); //Scaffold
}

Example 2: flutter raised button with icon

FlatButton.icon(onPressed: null, icon: null, label: null);
RaisedButton.icon(onPressed: null, icon: null, label: null);