Can you name the main data structures used in programming?

The main data structures in programming include:

• Arrays — ordered collections of elements of fixed size.
• Lists — dynamic collections, for example, List<T> in C#.
• Stack — a structure with access based on LIFO (last-in, first-out).
• Queue — a structure with access based on FIFO (first-in, first-out).
• Hash tables (Dictionary, Hashtable) — for quick access by key.
• Trees (e.g., binary search trees) — hierarchical structures for sorted data.
• Graphs — for representing network connections.

Example of using a stack in C#:

Stack<int> stack = new Stack<int>();
stack.Push(1);
stack.Push(2);
int top = stack.Pop(); // top == 2