What does the push_back() method do in a vector?

The push_back() method in a vector serves to add a new element at the end of the vector. This operation modifies the vector by increasing its size by one and placing the specified element in the newly created last position. This is a commonly used method in C++ because it enables dynamic appending of elements to collections without needing to manually manage the underlying array size.

When using push_back(), it is important to note that if the vector reaches its capacity, C++ automatically allocates more memory to accommodate the additional elements, making it easy for developers to modify collections without worrying about their sizes. This functionality is one of the reasons why vectors are so widely used in C++ programming for managing dynamically sized arrays.