Array Methods

Part of the Fundamentals section of Coddy's C# journey — lesson 58 of 69.

Arrays are packed with many methods (functionalities). To access a method, write:

Array.MethodName(arrayName, otherParameters)

Common Array Methods:

Clear(array, index, length) - clears the elements of an array, setting a range of elements to zero, false, or null:

int[] numbers = {1, 2, 3, 4, 5};
Array.Clear(numbers, 1, 3);
// numbers will be {1, 0, 0, 0, 5}

Reverse(array) - reverses the order of the elements in an array:

int[] numbers = {1, 2, 3, 4, 5};
Array.Reverse(numbers);
// numbers will be {5, 4, 3, 2, 1}

Sort(array) - sorts the elements in an array in ascending order:

int[] numbers = {5, 2, 9, 1, 5, 6};
Array.Sort(numbers);
// numbers will be {1, 2, 5, 5, 6, 9}

Copy(sourceArray, sourceIndex, destinationArray, destinationIndex, length) - copies a range of elements from one array to another:

int[] source = {1, 2, 3, 4, 5};
int[] destination = new int[5];
Array.Copy(source, 0, destination, 0, 5);
// destination will be {1, 2, 3, 4, 5}

Example with different positions:

int[] source = {1, 2, 3, 4, 5};
int[] destination = new int[7];
Array.Copy(source, 1, destination, 2, 3);
// destination will be {0, 0, 2, 3, 4, 0, 0}
// Copied elements 2, 3, 4 from source starting at index 1
// Placed them in destination starting at index 2

Challenge

Easy

Create a method named Merge that receives two arrays as arguments. The method merges the two arrays into one sorted array and returns it.

For example the following arguments: Merge(new string[] {"1", “4”, “2”}, new string[] {"2", “5”, “9”}) will return ["1", “2”, “2”, “4”, “5”, “9”]

Use Array.Copy() to copy elements from one array to another. The syntax is:

Array.Copy(sourceArray, sourceStartPosition, destinationArray, destinationStartPosition, length)

For example:

// Source array
string[] sourceArray = {"1", "2", "3", "4", "5"};

// Destination array
string[] destinationArray = new string[5];

// Copy elements from sourceArray to destinationArray
Array.Copy(sourceArray, 0, destinationArray, 0, 5);

Destination array after copy: 1 2 3 4 5

Cheat sheet

Arrays have built-in methods accessed with Array.MethodName() syntax:

Clear(array, index, length) - sets elements to zero, false, or null
Reverse(array) - reverses element order
Sort(array) - sorts elements in ascending order
Copy(sourceArray, sourceIndex, destinationArray, destinationIndex, length) - copies elements between arrays

Examples:

int[] numbers = {1, 2, 3, 4, 5};
Array.Clear(numbers, 1, 3);
// numbers will be {1, 0, 0, 0, 5}

int[] numbers = {1, 2, 3, 4, 5};
Array.Reverse(numbers);
// numbers will be {5, 4, 3, 2, 1}

int[] numbers = {5, 2, 9, 1, 5, 6};
Array.Sort(numbers);
// numbers will be {1, 2, 5, 5, 6, 9}

int[] source = {1, 2, 3, 4, 5};
int[] destination = new int[5];
Array.Copy(source, 0, destination, 0, 5);
// destination will be {1, 2, 3, 4, 5}

Try it yourself

using System;


public class Program {
    public static string[] Merge(string[] arr1, string[] arr2) {
        // Write code here
    }

    public static void Main(string[] args) {
        string textArr1 = Console.ReadLine();
        string textArr2 = Console.ReadLine();
        string[] arr1 = textArr1.Split(",");
        string[] arr2 = textArr2.Split(",");

        string[] mergedArray = Merge(arr1, arr2);
        Console.WriteLine(string.Join(", ", mergedArray));
    }
}