How can i store New Object in Vector?

Question

I am having trouble figuring out how i can store new object into a vector, and be able to pull that information out.

What i am trying to do is, storing different data from files in a series of objects, then going through these objects and pulling out the information.

I am looking for something like this:

vector<myClass> list;
while( i < nFiles)
{
   myClass *temp = new myClass;
   list.push_back(temp);       

   temp->setSomething();

   i++;
}

I want to have a different object for every nFile cycle, so i am able to later go through each object and pull the information out from each object.

I've tried pushing the temp to a vector but its giving me nothing but errors.

Is what i'm trying to do programatically correct? I can't get my head around this. Any sort of help would be much appreciated. Thank you.

If you've actually read the errors *and a mandatory C++ book you surely have*, you'd know what's wrong. — Griwes, Sep 18 '13 at 20:57

score 5 · Answer 1 · answered Sep 18 '13 at 21:03

5

First a bit of vocabulary: You don't want to store classes in the array (actually, vector), you want to store objects. Objects are instances of classes.

Second, you've got the syntax of the while loop wrong. Look it up in a C++ book. Better use a for loop.

Third, always write MyClass the same way. Don't change lower-/upper case.

And finally, learn about the difference between pointer to objects and objects. The element type you specify when you declare the vector doesn't match the things you put into it.

answered Sep 18 '13 at 21:03

Sebastian

1,839
12
16

Sorry, should of taken the time to proof read my question. I'm not as clueless as i just made myself sound, just haven't had much sleep. Thanks for taking the time to help! – nub Sep 18 '13 at 21:12
@Ey0o: After the [Balmer-Peak](http://xkcd.com/323/) comes insanity (sleep deprivation has similar effects as alcohol consumption). Got to bed! – bitmask Sep 18 '13 at 21:16

score 1 · Answer 2 · answered Sep 18 '13 at 21:04

1

the syntax is while (...) not (while ...) AND you cant say i=1 in the while loop parameters. What you wanna do is:

either :

 int i = 1;
 while (i < nFiles){
   //Do something
 }

OR

for (int i = 1; i < nFiles; i++){
  //Do something
}

answered Sep 18 '13 at 21:04

Rahul Shardha

399
7
16

score 0 · Accepted Answer · edited Sep 18 '13 at 21:34

0

Your vector should either be a vector of pointers to myClass, i.e.,

vector<myClass *> list;

Or your temp shouldn't be a pointer, i.e.,

myClass temp;

The latter means the whole temp object is copied when you do list.push_back (byte by byte).

edited Sep 18 '13 at 21:34

greatwolf

20,287
13
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105

answered Sep 18 '13 at 21:08

Miichi

1,739
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16

1

Only when you use pointers, this part modifies the object in the vector: temp->setSomething();. But you have to do manual memory Management. Consider using smart pointers. – Sebastian Sep 18 '13 at 21:19
You 1) failed at pointer syntax and 2) never want to store a raw pointer in any container. – Griwes Sep 18 '13 at 21:28
And you also failed at the "byte by byte" part. – Griwes Sep 18 '13 at 21:35
@Griwes: I don't understand your first comment. The pointer sytax of Miichi looks fine. – Sebastian Sep 18 '13 at 21:45
@Sebastian, yes, now it does, because it got corrected. Maybe it's time for you to explore the wonderful world of [post history](http://stackoverflow.com/posts/18882392/revisions) feature? :) – Griwes Sep 18 '13 at 21:54

How can i store New Object in Vector?

3 Answers3