How do I get checkbox value to be used in another function?

I have a widget that displays a checkbox. The checkboxes display days of the week. I am curious to know how I can use the values below in another function? For example, how can I know in another function what the user has selected in terms of a week day?

Here is my checkbox widget code:

  bool monVal = false;
  bool tuVal = false;
  bool wedVal = false;
  bool thurVal = false;
  bool friVal = false;
  bool satVal = false;
  bool sunVal = false;

  Widget checkbox(String title, bool boolValue) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[
        Text(title),
        Checkbox(
          value: boolValue,
          onChanged: (bool value) {
            /// manage the state of each value
            setState(() {
              switch (title)
              {
                case "Mon":
                  monVal = value;
                  print(value);
                  break;
                case "Tu":
                  tuVal = value;
                  print(value);
                  break;
                case "Wed":
                  wedVal = value;
                  print(value);

                  break;
                case "Thur":
                  thurVal = value;
                  print(value);

                  break;
                case "Fri":
                  friVal = value;
                  print(value);

                  break;
                case "Sat":
                  satVal = value;
                  print(value);

                  break;
                case "Sun":
                  sunVal = value;
                  print(value);

                  break;
              }
            });
          },
        )
      ],
    );
  }

the print(value) is pointless.. I just tried that to see if I could get the day of the week selected, but its only going to return true or false.

Many thanks friends