Referring to an unknown element

[Daniel Primed]

I posted about this in another help thread a week or so ago but it was only a quick side note. Now its really starting to bother me. I am creating a program in which the user any amount of names and school results in. I’m pretty much done. Except that I am unsure about how to refer the names. Since I can’t say to begin with how many names there are going to be so I can’t print x amount of elements.

To summarise

-I’m using vectors

-user defines no of elements in the vectors

-how do I print the elements(refer to them individually, so that its flexible enough)

I’m not sure if I can just use the size and say print the element which is the size-(size-1) to refer to the first element and just increase the size of 1 as I go. Then once I get to a blank element just print some kinda of end message. If I could do something like that how would I do it.

Thank you for the help.

[ZuK]

You say you are using vector. So there is no need to specify any size of the vector.
Just insert new elements wit push_back() ( this will automatically adjust the vector's size ), then there won't be any "empty" elements in the vector ( this just happens if you create your vector with a certain size or call resize on it ) You can get the actual size of the vector by calling size() on the vector.
To access idividual elements you can use operator [].
Kurt

[hk_mp5kpdw]

So, your question is about printing all the elements of a vector? As an example:

#include <string>
#include <iterator>
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

struct person
{
    string name;
    int age;
    person(string n,int a) : name(n), age(a) {}
};

// Overloaded stream insertion operator
ostream& operator<<(ostream& os,const person& p)
{
    return os << p.name << " is " << p.age << " years old.";
}

int main()
{
    vector<person> people;
    vector<person>::size_type loop;
    vector<person>::iterator it;

    // Insert person objects onto vector.
    people.push_back(person("Homer",42));
    people.push_back(person("Lisa",10));
    people.push_back(person("Bart",12));

    // Print method #1 use manual loop and manual printing w/ indexing
    for( loop = 0; loop < people.size(); ++loop )
    {
        cout << people[loop].name << " is "
             << people[loop].age << " years old."
             << endl;
    }

    // Print method #2 use manual loop and manual printing but w/ iterators
    for( it = people.begin(); it != people.end(); ++it )
    {
        cout << it->name << " is "
             << it->age << " years old."
             << endl;
    }

    // Print method #3 use manual loop and indexing but with operator<<
    for( loop = 0; loop < people.size(); ++loop )
    {
        cout << people[loop] << endl;
    }

    // Print method #4 use copy STL function... (uses operator<<)
    copy(people.begin(),people.end(),ostream_iterator<person>(cout,"\n"));
    cout.flush();

    return 0;
}

All of those methods should output the same thing, so you should have 4 copies of the following:

Homer is 42 years old.
Lisa is 10 years old.
Bart is 12 years old.

There are other ways as well, you could use a manual loop with iterators that uses the overloaded operator<< for example.