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Arrays in C#

Arrays in C# are used to store multiple values of the same type in a single variable. They are a fundamental data structure for handling collections of data.

1. Declaring and Initializing Arrays​

In C#, arrays are declared by specifying the type of elements and the square brackets [].

Syntax:​

type[] arrayName = new type[size];

Example:​

int[] numbers = new int[5]; // Array of 5 integers

You can also initialize an array with values:

int[] numbers = { 1, 2, 3, 4, 5 };

2. Accessing Array Elements​

Array elements can be accessed by their index, with the first element at index 0.

Example:​

int[] numbers = { 10, 20, 30, 40, 50 };
Console.WriteLine(numbers[2]); // Outputs 30

3. Modifying Array Elements​

You can modify elements by assigning a new value to a specific index.

Example:​

int[] numbers = { 10, 20, 30, 40, 50 };
numbers[2] = 100; // Changes the value at index 2 to 100
Console.WriteLine(numbers[2]); // Outputs 100

4. Looping Through Arrays​

Arrays can be traversed using loops, such as for or foreach.

Using a For Loop​

int[] numbers = { 1, 2, 3, 4, 5 };
for (int i = 0; i < numbers.Length; i++) {
    Console.WriteLine(numbers[i]);
}

Using a Foreach Loop​

int[] numbers = { 1, 2, 3, 4, 5 };
foreach (int num in numbers) {
    Console.WriteLine(num);
}

5. Multi-Dimensional Arrays​

C# supports multi-dimensional arrays, like 2D arrays, which can be used for representing data in a grid format.

Syntax:​

type[,] arrayName = new type[rows, columns];

Example:​

int[,] matrix = new int[3, 3]; // 3x3 matrix
matrix[0, 0] = 1; // Assigning value to the first element

Initializing a 2D Array​

int[,] matrix = {
    {1, 2, 3},
    {4, 5, 6},
    {7, 8, 9}
};
Console.WriteLine(matrix[1, 1]); // Outputs 5

6. Array Class Methods​

The Array class in C# provides several useful methods for array manipulation.

  • Length: Returns the number of elements.
  • Sort(): Sorts the elements in ascending order.
  • Reverse(): Reverses the order of elements.

Example:​

int[] numbers = { 5, 3, 8, 1, 4 };
Array.Sort(numbers); // Sorts the array
Array.Reverse(numbers); // Reverses the array

Summary​

Arrays in C# are essential for managing collections of data. Understanding how to declare, initialize, and manipulate arrays will help you effectively handle data in your programs.

Happy coding!