Before we can start delving into LINQ, we need to first understand the underlying principles upon which it is built. LINQ is all about operations over collections, so, you’ve guessed it: we will be dealing with collections.
You already learned that of all data structures, arrays are the fastest, because they are unsorted non-generic data structures.… Read more
Surprisingly, you will notice that we have already used these data structures before, without knowing they were data structures: the class and the structure. Whenever we instantiate one of these, we are actually using it as a data structure (more or less).… Read more
Sorted Set is the preferred data structure when we want to have sorted items and also to eliminate duplicate elements. Unfortunately, its performance is worse than that of a Hash Set or a Dictionary. The following program declares a new Sorted Set and adds elements to it:
There are two types of Sets in the System.Collections.Generic namespace: SortedSet and HashSet. Both of them offer the functionality of storing non-duplicate items. The main difference between them is the fact that the SortedSet obviously has its items sorted. Therefor, if you do not care about the order in which the items are stored, you are better off performance-wise to use a HashSet.… Read more
Sorted Dictionary is just a normal Dictionary data structure, but with its keys sorted. Of course, it is obvious that having its elements sorted will make this data structure slightly slower than a normal Dictionary, but it does offer the advantage of making an in memory sorted lookup very easy.… Read more
The data structure Dictionary suggests storing key-value pairs and provides a quick search by key. In common language, this means that instead of elements receiving a numerical index, as in the array case, they receive a specific type as a key (this is what the K stands for in the Dictionary<K, T> concept; T stands for the type of the values stored in the dictionary) for accessing elements.… Read more
Queue is a linear data structure in which there are two operations defined: adding an element to the tail (enqueue) and extract the front-positioned element from the head (dequeue). These two operations take a constant time to execute, because the queue is usually implemented with a linked list.… Read more
Stack is a linear data structure in which there are 3 operations defined: adding an element at the top of the stack (push), removing an element from the top of the stack (pop) and inspect the element from the top without removing it (peek).… Read more
Singly and doubly linked lists (also known simply as Linked Lists) hold collection of elements, which preserve their order. Their representation in the memory is dynamic, pointer-based. They are linked sequences of elements. Adding is a fast operation, but it is a bit slower than adding to a List, because every time when we add an element to a linked list, we allocate a new memory area.… Read more
