What are iterator types in C++?
What are iterator types in C++ and how do I use them?
Iterator types in C++ define how iterators access elements in a container. The most common types are:
- Input Iterator: Read elements from a sequence.
- Output Iterator: Write elements to a sequence.
- Forward Iterator: Traverse a sequence in one direction.
- Bidirectional Iterator: Traverse a sequence in both directions.
- Random Access Iterator: Access any element in constant time.
In most cases, using auto for the return type of begin() and end() is sufficient. However, if you need to specify the type explicitly, you can use the iterator type provided by the container. Here's how to do it with std::vector:
#include <vector>
#include <string>
class Player {
public:
Player(std::string Name) : mName(Name) {}
std::string GetName() const { return mName; }
private:
std::string mName;
};
class Party {
public:
void AddMember(const std::string& NewMember) {
PartyMembers.emplace_back(NewMember);
}
std::vector<Player>::iterator begin() {
return PartyMembers.begin();
}
std::vector<Player>::iterator end() {
return PartyMembers.end();
}
private:
std::vector<Player> PartyMembers;
};
int main() {
Party MyParty;
MyParty.AddMember("Legolas");
MyParty.AddMember("Gimli");
MyParty.AddMember("Frodo");
for (const auto& Player : MyParty) {
std::cout << Player.GetName() << '\n';
}
}Legolas
Gimli
FrodoImplementing Ranges for Custom Types
Learn to implement iterators in custom types, and make them compatible with range-based techniques.