calculus-logic-calculator.dart

class _CalculatorInputState extends State<CalculatorInput> {
  ...
  num get calculatorValue {
    switch (operation) {
      case Operation.addition:
        return operandA + operandB;
      case Operation.subtraction:
        return operandA - operandB;
      case Operation.multiplication:
        return operandA * operandB;
      case Operation.division:
        return operandA / operandB;
      case Operation.sqrt:
        return sqrt(operandA);
      default:
        return 0;
    }
  }

  String get calculatorFormat {
    switch (operation) {
      case Operation.addition:
        return '$operandA + $operandB';
      case Operation.subtraction:
        return '$operandA - $operandB';
      case Operation.multiplication:
        return '$operandA * $operandB';
      case Operation.division:
        return '$operandA / $operandB';
      case Operation.sqrt:
        return 'sqrt($operandA)';
      default:
        return '';
    }
  }
  ...
}