How to sort an STL vector?

Question

I would like to sort a vector

vector<myClass> object; 

Where myclass contains many int variables. How can I sort my vector on any specific data variable of myClass.

Answer 1

std::sort(object.begin(), object.end(), pred()); 

where, pred() is a function object defining the order on objects of myclass. Alternatively, you can define myclass::operator<.

For example, you can pass a lambda:

std::sort(object.begin(), object.end(),           [] (myclass const& a, myclass const& b) { return a.v < b.v; }); 

Or if you're stuck with C++03, the function object approach (v is the member on which you want to sort):

struct pred {     bool operator()(myclass const & a, myclass const & b) const {         return a.v < b.v;     } }; 

Answer 2

Overload less than operator, then sort. This is an example I found off the web...

class MyData { public:   int m_iData;   string m_strSomeOtherData;   bool operator<(const MyData &rhs) const { return m_iData < rhs.m_iData; } };  std::sort(myvector.begin(), myvector.end()); 

Source: here