Searching the contents of a vector

How do I perform a search operation on the contents of a vector?

My vector looks like this (the beginning of it):

Code:

---

int main(void)
{
        vector<Transaction> trans; //instantiates a vector called trans

        // sample records in the vector
        trans.push_back(Transaction(1365,"Norwich","20030901","1200",12,005,"Nobody present"));

---

I need to search the vector for each occurence of a date, format it, and then output it to the screen.
Thanks.

Use the find function in the STL, I think it's in <algorithm>.

You can use the find_if() algorithm with a predicate. Here is some code assuming that the date is stored as a std::string and that Transaction has a member function get_date() that returns the date.

Predicate:

Code:

---

class DateMatcher
{
public:
  DateMatcher(const std::string& str)
  : date(str)
  {}

  bool operator()(const Transaction& trans)
  {
    if(trans.get_date() == date) return true;
    return false;
  }

private:
  std::string date;
};

---

Using the algorithm:

Code:

---

  std::vector<Transaction> transactions;
  std::vector<Transaction>::iterator found;

  found = std::find_if(transactions.begin(), transactions.end(), DateMatcher("20030901"));

  if(found == transactions.end())
  {
    std::cerr << "Not found!" << std::endl;
  }
  else
  {
    Transaction& trans = *found;
  }

---

Quote:

---

Originally posted by thefroggy
You can use the find_if() algorithm with a predicate. Here is some code assuming that the date is stored as a std::string and that Transaction has a member function get_date() that returns the date.

Predicate:

Code:

---

class DateMatcher
{
public:
  DateMatcher(const std::string& str)
  : date(str)
  {}

  bool operator()(const Transaction& trans)
  {
    if(trans.get_date() == date) return true;
    return false;
  }

private:
  std::string date;
};

---

Using the algorithm:

Code:

---

  std::vector<Transaction> transactions;
  std::vector<Transaction>::iterator found;

  found = std::find_if(transactions.begin(), transactions.end(), DateMatcher("20030901"));

  if(found == transactions.end())
  {
    std::cerr << "Not found!" << std::endl;
  }
  else
  {
    Transaction& trans = *found;
  }

---

---

Thanks. I have tried this, but I get an error message saying 'get_date': is not a member of Transaction. Any ideas what I'm doing wrong?

Quote:

---

Here is some code assuming that the date is stored as a std::string and that Transaction has a member function get_date() that returns the date.

---

Notice that I assumed a few things when I wrote the code. You'll either have to add a get_date() method to your Transaction class, or change the DateMatcher class to match the date in some other way.