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Do the parentheses after the type name make a difference with new?
What do the following phrases mean in C++: zero-, default- and value-initialization?
I've used vector without any problem but i still have a question about it. I always use code like this,
vector<int>* v1 = new vector<int>;
so, can i use:
vector<int>* v2 = new vector<int>();
I know what () does, but whats the difference? In v1, does vector ever initialize any integer?
First your question: new calls the default constructor, you don't need to do this "manually". But then: Try to use value types as often as possible in C++. They are not only faster, but also easier and safer, because the destructor gets automaticly called when leaving the scope. So just write
std::vector<int> v; // Calls default constructor
If you really need the heap, try using smart pointers such as shared_ptr and unique_ptr, this way you can't forget to call delete. (And delete also calls the destructor, no need to do this manually.)
Both statements are the same. The constructor taking no parameters will be called in both cases.
