Decimal Flutter

Question

Gentlemen, good night!

I have a problem in my calculation because it is coming out broken values, Ex: 13,3434

I would like you to leave only 13,34.

Follow the code for better viewing.

Future calculate() {
double precototal1 =
    double.parse(_precoCtrl.text.replaceAll(new RegExp(r'[,.]'), '')) * 12;
double precototal2 =
    double.parse(_precoCtrl1.text.replaceAll(new RegExp(r'[,.]'), '')) * 12;
double unidademl1 =
    double.parse(_unitCtrl.text.replaceAll(new RegExp(r'[,.]'), ''));
double unidademl2 =
    double.parse(_unitCtrl1.text.replaceAll(new RegExp(r'[,.]'), ''));

double difvalor = 0;
double latas = 0;
double litros = 0;
double totlitros = 0;
double diflitros = 0;

setState(() {
  _completed = false;
  _busy = true;
});

return new Future.delayed(const Duration(seconds: 1), () {
  setState(
    () {
      print(formatter.format(precototal2));
      if (precototal1 > precototal2) {
        difvalor = precototal1 - precototal2;
        latas = (difvalor / precototal2);
        litros = (latas * unidademl2);
        totlitros = litros + unidademl2;
        diflitros = (totlitros - unidademl1);
      } else {
        difvalor = (precototal2 - precototal1);
        latas = (difvalor + precototal1);
        totlitros = litros + unidademl1;
        litros = (latas / unidademl1);
        diflitros = (unidademl2 - totlitros);
      }

Answer 1

From what I understand, your wish is to keep the same number of houses after the decimal point:

12,12345 turns 12,12

0,012345 becomes 0,012

If this is really your case, you can use the method of a: toStringAsFixed

The parameter that this function receives is the number of decimal places, in your case, 2:

var numero = 13.3434;
print (numero.toStringAsFixed(2)); //printa 13.34

This turns your variable into a string. If you want it to stay as double, you can parse it later:

var numero2 = double.parse(numuero.toStringAsFixed(2));