Question

so i am doing a inventory program. I have a vector of class items in it and I want to user enter Id and then run an iterator to match with the Id that is in the vector and change the value of the quantity sold:

here is part of my code:

 vector<Item>::const_iterator it;
  for(it=items.begin(); it !=items.end(); it++){
    if (it->getID() == id){
      amount=it->getactual()-sold;
      it->setactual(amount);

that is in my class

int getactual()const{return actual_quantity;}
void setactual(int quantity){actual_quantity=quantity;}

but i get an error: passing ‘const Item’ as ‘this’ argument of ‘void Item::setactual(int)’ discards qualifiers

Answer 1

You should use

vector<Item>::iterator

instead of

vector<Item>::const_iterator

const_iterator means read-only.