What is a vector used for in C++?

A vector in C++ is primarily used as a dynamic size array. This means that while a standard array has a fixed size determined at compile-time, a vector allows for resizing at runtime. When elements are added to a vector and it reaches its current capacity, the vector automatically allocates more memory, typically doubling its current size, to accommodate additional elements. This capability makes vectors particularly useful in situations where the number of elements is not known beforehand or when dealing with collections of varying sizes.

Vectors provide several advantages over fixed-size arrays, including ease of use for inserting or removing elements, built-in functions for managing size and capacity, and the ability to hold any data type. The flexibility of vectors allows programmers to work efficiently with dynamic data structures without worrying about memory allocation intricacies.