Arrays
Arrays in C# are very similar to arrays in C. They are defined using the brackets operator [], and
they are initialized using a list defined with curly braces. For example:
int[] nums = { 1, 2, 3, 4, 5 };
We can also define an empty array like this:
int[] nums = new int[10];
To get the size of the array, use the Length method.
int[] nums = new int[10];
Console.WriteLine(nums.Length);
To access a specific item in the array, we use the brackets operator:
int[] nums = new int[10];
int firstNumber = nums[0];
int secondNumber = nums[1];
nums[2] = 10;
Notice that C# uses zero based indices.
Multidimensional arrays
C# supports multidimensional arrays, defined in the following manner:
int[,] matrix = new int[2,2];
matrix[0,0] = 1;
matrix[0,1] = 2;
matrix[1,0] = 3;
matrix[1,1] = 4;
int[,] predefinedMatrix = new int[2,2] { { 1, 2 }, { 3, 4 } };
Jagged arrays
These are multidimensional arrays where each subarray is an independent array - Can have subarrays of different lengths. Use a separate set of square brackets for each dimension of the array.
jagArray1[2][7][4] // Three sets of square brackets
Unlike other types of arrays, you cannot fully instantiate a jagged array in a single step. Since a jagged array is an array of independent arrays, each array must be created separately.
Instantiating a full jagged array requires the following steps:
##### 1. Instantiate the top-level array. ##### 2. Instantiate each subarray separately, assigning the reference of the newly created array to the appropriate element of its containing array.
For example, the following code shows the declaration, instantiation, and initialization of a twodimensional jagged array. Notice in the code that the reference to each subarray is assigned to an
element in the top-level array.
int[][] Arr = new int[3][];
Arr[0] = new int[] {10, 20, 30};
Arr[1] = new int[] {40, 50, 60, 70};
Arr[2] = new int[] {80, 90, 100, 110, 120};
Exercise
Define an array called fruits that holds the following strings: "apple", "banana", and "orange".
