How do I resize a vector in C++ STL?

How do I resize a vector in C++ STL?

You can resize a vector in C++ using the resize() member function. For example, vec.resize(new_size); will change the size of the vector to new_size.

What happens to the elements when I resize a vector?

If you increase the size, new elements are default-initialized. If you decrease it, elements are removed from the end.

Can I use resize() to shrink a vector to zero?

Yes, calling resize(0) will effectively clear the vector, removing all elements.

Are there any performance considerations when resizing?

Yes, resizing can involve reallocating memory, which may affect performance. It's better to reserve space if you know the size in advance.