getCalcOperationSymbol function
Implementation
String? getCalcOperationSymbol(CalcOperation? op) {
if (op == null) return null;
switch (op) {
case CalcOperation.sum:
return '+';
case CalcOperation.subtract:
return '-';
case CalcOperation.multiply:
return '*';
case CalcOperation.divide:
return '/';
default:
return null;
}
}