Thread: Reading Data

I just can't figure out how I can extract the name and all the numbers into seperate variables in the code to later be processed.

Use formatted input, e.g. cin >> x;
If the name is just a word, x would then be a string, then for the numbers it would be some numeric type like int.

I dont know how many lines there are to read from.

Use a vector.

The in would do the same thing wouldn't? Would it skip over the spaces and move to the number after the name?

If this 'in' that you speak of is a std::istream, yes.

Also what would happen when it got to the end of the line?

Iterate over the next line. You know the exact format, after all.

I'm still relatively new to C++ so could you explain what you mean using a vector?

At the moment, dont think about reading all the lines. First, how would you read in a single line into your struct?

I don't believe in using all the standard template library crapola until you understand alot of the friggin' language.

Telling someone to 'use a vector' when they barely know what a struct is can't be a good idea and I can't stand people who make such suggestions.

Go read Accelerated C++: Practical Programming by Example by Andrew Koenig and Barbara E. Moo

Basically, a vector is a container that can store multiple values. Think of it as a resizable array; it automatially resizes itself whenever needed eg. when you add an element.

One important feature is that you can create a vector to hold elements of any type you like; int, double or even your own structs/classes. It's simply a *container*, an empty shell to store other objects.

Example:

Code:

#include <vector>

//like cout, vector is part of std
using namespace std;

int main()
{
    //our vector will be named X, and will hold values of type int
    vector <int> X;
    //our second one holds doubles
    vector <double> Y;
    
    //add an element to vector; resizing is done automatically
    X.push_back(1);
    int n = 123;
    X.push_back(n);
    
    n = some_function();
    X.push_back(some_function());
    
    
    //now retrieve values
    //basic way would be to use size() in the vector
    for(int i = 0; i < X.size(); ++i)
    {
        cout << "Element #" << i << " is " << X[i] << "\n";
    }
}

Hope that helps. There are lots of stuff about vectors and other similiar standard C++ library containers out there on the net, just Google around.