Changes on elements in a Vector

[gmYoshi]

Hi, I've got a problem using the Vector-class. When using it to implement a version of Dijkstra's algorithm I ran into reference-issues, so I tried this out:

cout << myVector[0].getColor();
myVector[0].setColor(myVector[0].getColor()+1);
cout << " " << myVector[0].getColor();
getColor and setColor are simple getter and setter for an integer-value. The above listed code results in the following output: "1 1", which isn't exactly what I'd like to happen. Can someone help me please? What do I have to change in order to get "1 2" put out?

[daveD]

Hi,

Can you post the code from the "getter" and "setter" so we can see what you are doing in there?

[gmYoshi]

Of course but that's really harmless:

int getColor(){
return color;
};
void setColor(int c){
color=c;
};

[daveD]

Have you tried passing though some different values to setColor()?

eg.
cout << myVector[0].getColor();
myVector[0].setColor(7);
cout << " " << myVector[0].getColor();

See what happens. Maybe this will help you find where the problem is..

[gmYoshi]

This doesn't work either. On top of that, I found another strange thing. Consider the following two lines:

cout << *(c->vertices.at(0)) << endl << g->getVertices().at(0) << endl;
cout << *(c->vertices.at(0)) << endl;

The first line prints the excepted result ("Vertex 001 with label A
Vertex 001 with label A).
It also does it repeatedly. The second line doesn't do what it's intended to do at all. It prints out "Vertex " and then doesn't print out anything anymore, even if I put the working line after it. I'm quite confused as I don't understand why the first line works and the second one doesn't. If it helps: g is a Graph and c is a Component, which holds certain vertices of g in its member vertices. These are the vectors I meant when I wrote "myVector" above.

[Scott Vass]

I try to avoid the subscript operator whenever iterators are available. I realize Dijkstra's algorithm indexes into arrays, and I seem to recall they were arrays of distance values...
Anyway, I hope this helps.

class myClass {
private:
	int color;
public:
	myClass() {color=0;}
	~myClass(void) {}
	void setColor(const int &c) {color=c;}
	int getColor() const {return color;}
};

int main()
{
	vector<myClass> myVector;
	myClass mc;
	mc.setColor(1);
	myVector.push_back(mc);
	// Your code. Output:  1 2
	cout << myVector[0].getColor();
	myVector[0].setColor(myVector[0].getColor()+1);
	cout << " " << myVector[0].getColor();
	// My code. Same results
	vector<myClass>::iterator iter=myVector.begin();
	cout << (*iter).getColor();
	(*iter).setColor((*iter).getColor()+1);
	cout << " " << (*iter).getColor();
	return 0;
}