Calculate from one TextField in flutter

I'm creating a flutter page that has one text field, user should put a number in this field and the page calculate his input with another int that i already added in the code.

i did it in a bad way as you can see below

first under the screen class i did

  TextEditingController num1controller = TextEditingController();
  int calculation = 10;
  String result = '0';

then I created a text field

                  controller: num1controller,
                  showCancelIcon: true,
                  autocorrect: false,
                  enableSuggestions: false,
                  keyboardType: TextInputType.number,
                  decoration: InputDecoration(
                    labelText: 'Label Text',
                    hintText: 'Hint Text',

then i did the calculation as follows using an ElevatedButton

                child: const Text('Calculate'),
                onPressed: () {
                  setState(() {
                    int sum = int.parse(num1controller.text);
                    var sum1 = sum ~/ calculation;
                    result = sum1.toString();

Then i showed the results as follows:


Is it correct the way i did it? or should it be done in a better way? also How i can make result accepts decimal points? currently the result is not showing any decimal points?


  • You are doing integer division by adding ~ on sum ~/ calculation. It is also better using .tryPerse. If you like to accept double from TextFiled use double sum.

    Instead of .toString(), you can use toStringAsFixed(2) on to show decimal point number.

    I will prefer like

    setState(() {
      double sum = double.tryParse(num1controller.text)??1;
      final sum1 = sum / calculation;
      result = sum1.toStringAsFixed(2);