C# Arrays
An array lets you store many values of the same type in a single variable, instead of declaring a separate variable for each value. If you needed to keep track of five student scores, you could create five variables, but that quickly gets messy. An array holds them all together and gives each one a numbered position.
Creating an Array
To declare an array, write the type followed by square brackets. You can create an empty array of a fixed size, or you can fill it with values right away using curly braces. Each value in an array is called an element.
Declaring and initializing arrays
// An array that will hold 4 strings
string[] cars = {"Volvo", "BMW", "Ford", "Mazda"};
// An empty array of 3 integers (defaults to 0)
int[] scores = new int[3];
Console.WriteLine(cars[0]); // Volvo
Console.WriteLine(scores[0]); // 0Accessing Elements
You access an element by its index. Array indexes start at 0, so the first element is at index 0, the second at index 1, and so on. Using an index that is too large will throw an IndexOutOfRangeException at runtime.
Reading and changing elements
string[] cars = {"Volvo", "BMW", "Ford", "Mazda"};
Console.WriteLine(cars[1]); // BMW
// Change the value at index 0
cars[0] = "Opel";
Console.WriteLine(cars[0]); // OpelArray Length
Every array has a built-in Length property that tells you how many elements it contains. This is very useful when you loop through an array, because the count comes straight from the array itself.
Using the Length property
string[] cars = {"Volvo", "BMW", "Ford", "Mazda"};
Console.WriteLine(cars.Length); // 4Common ways to create arrays
Exercise: C# Arrays
Once a C# array is created with a given length, can that length change?
