Compute wages using hourly rate and hours worked.

main.dart

void main() {
  double hourlyRate = -0.5;
  int hoursWorked = 12;
  print(computeWages(hourlyRate , hoursWorked));
}
computeWages (hourlyRate , hoursWorked) {
  var wages = hourlyRate * hoursWorked;
  if(hourlyRate<=0||hoursWorked<=0){
    throw('Negative values not allowed');
  }
  else {
    return wages;
  }    
}