3. Arrays

Arrays in C#

Arrays are collections of elements that share the same data type. In C#, arrays are reference types stored in the heap. Passing an array to a method sends the reference, meaning any change made inside the method affects the original array.

Declaration and Initialization

// Shorthand
string[] students = { "Rocky", "Arif", "Leyla" };

// Long form
string[] students2 = new string[] { "Rocky", "Arif", "Leyla" };

Both forms create an array of string elements. Since they are reference types, they are allocated on the heap.

Array Properties and Methods

array.Length

Provides the number of elements in the array. Internally, it’s accessed via a getter.

Cloning an Array

Clone() returns a new object with the same contents at a different memory location.

string[] students = { "Rocky", "Arif", "Leyla" };
string[] stud_clone = students.Clone() as string[];
students[0] = "Salam";

if (stud_clone != null)
{
    foreach (string student in stud_clone)
    {
        Console.WriteLine(student);
    }
}

In the above example:

• students.Clone() returns a new object identical to students.

• as string[] attempts to cast the clone to a string[], returning null if it cannot.

• Changes in students do not affect stud_clone after the clone is made.

Alternatively, you can use the is pattern:

string[] students = { "Rocky", "Arif", "Leyla" };
var obj = students.Clone();

if (obj is string[] stud_clone)
{
    foreach (var item in stud_clone)
    {
        Console.WriteLine(item);
    }
}
else
{
    Console.WriteLine("I cannot convert");
}

Copy Method

Copy() is a string method that returns a new String object with the same characters but a different object reference.

string str1 = "Hello";
string str2 = string.Copy(str1);
// str1 == "Hello", str2 == "Hello", but str1 and str2 refer to different objects

Multidimensional Arrays

Rectangular Arrays

All rows must have the same number of columns.

int[,] rectangleArray = new int[3, 2]
{
    {1,2},
    {3,4},
    {5,6}
};

Jagged Arrays

An array of arrays, allowing each row to have a different length.

int[][] jaggedArray = new int[3][];
jaggedArray[0] = new int[2] { 1, 2 };
jaggedArray[1] = new int[3] { 3, 4, 5 };
jaggedArray[2] = new int[1] { 6 };

Reference

The content in this document is based on the original notes provided in Azerbaijani. For further details, you can refer to the original document using the following link:

Original Note - Azerbaijani Version