vector sort objects

[theChameleon]

hi... i need to sort a vector by particular class member variable... how do i do that?

class Example{
    private:
        string name;
        ...
    public:
        string getName(){return name;}
        void setName(string input){name = input;}
        ...
};

int main(){
    vector<Example> myVec;
    vector<Example>::iterator myIt;
    ...
    sort(....); //what must i write in this statement to make it sort by the name of all the example objs?
    ...
}

[Duthomhas]

It takes a little while to be able to read the docs perfectly:
http://www.cplusplus.com/reference/algorithm/sort.html

The second prototype includes a comparison function

template <class RandomAccessIterator, class Compare>
  void sort ( RandomAccessIterator first, RandomAccessIterator last, Compare comp );

Write yourself a little function that will compare two Examples based upon the name.

bool operator compare_examples ( const Example& a, const Example& b )
  {
  return a.getName() < b.getName();
  }

You can also just overload the < operator directly (replace the word "compare_examples" in the above example with "<").

You will also have to change the getName to be const-correct:
string getName() const { return name; }
(this is a requirement for the sort() algorithm --which deals with const object references, if I remember correctly).

Now you can sort() on the name, either by explicitly specifying a comparison function name, or by using the implicit, overloaded < operator.

Hope this helps.