# Introduction to Arrays

An array keeps many values of the same type together in one fixed-size container, like eggs in a carton.

Novice · C# · Updated November 3, 2026

## After this lesson you can

- Explain what an array is and when to use one

## Key takeaways

- An array keeps many related values together under one name, each in its own numbered spot.
- An array's size is fixed when you make it. For more values, you need a bigger array.
- Every value in an array has the same type: an `int[]` holds only whole numbers, a `string[]` only text.
- Use an array instead of separate variables such as `score1` and `score2`: the values travel together, and `Length` counts them.

So far, every variable you've made holds one value: one score, one price, one name. But real programs work with groups: a team's scores for every game, the prices in a shopping cart, the names in a class. An **array** lets you keep many related values together as one group, under one name.

## An egg carton

Think about buying eggs. Even if you buy them one at a time at a farmers' market, you'd still put them in a container to carry them home.

![A group of white eggs](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/09/18c6e94b66c540028f63b700f99c0eba.png)

Each egg is like a variable. Just as you want to keep your eggs together, you'll often want to keep values together. An egg carton is like an array: a container made for holding eggs, in numbered spots.

![A carton of eggs](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/09/4ab62186af3548108997a553d7661150.png)

## Fixed in size

An array has a fixed size. If you have a 6-egg carton, you can't stretch it to fit 12 eggs. You'd need a bigger carton, and you'd move the 6 eggs into it.

![A carton of eggs](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/09/5a0200f48b2a4facb124f8de4597c105.png)

Arrays work the same way: you choose the size when you make one, and it never changes.

## One type of thing

An array holds values of one type. You wouldn't put a dozen eggs in a 12-pack box made for soda cans. In the same way, an array of `string` values holds only text, and an array of `int` values holds only whole numbers.

![A carton of eggs and a box of soda](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/09/5e09613b88954bdb80b4e9ac8184cfe8.png)

## Why use an array?

Compare five separate variables with one array:

```csharp
int score1 = 80;
int score2 = 85;
int score3 = 90;
int score4 = 75;
int score5 = 95;

int[] scores = { 80, 85, 90, 75, 95 };
Console.WriteLine("Games played: " + scores.Length);
```

```text
Games played: 5
```

With separate variables, adding a sixth game means a new variable and new code everywhere you use them. With an array, the values travel together: you can pass all of them to a method at once, count them with `Length`, and, as you'll see in this chapter, visit every one of them with a loop.

## Check yourself

1 question to try on the lesson page.

## So what

Most interesting data comes in groups. An array is the simplest way to keep a group together: one name, one type, a fixed number of numbered spots.

## Key terms

- [Array](https://www.ask-codey.com/glossary/array-c-sharp)

## Cheat sheets

- [Introduction to Arrays](https://www.ask-codey.com/cheat-sheets/arrays-in-csharp-introduction-to-arrays-cheat-sheet)

Source: https://www.ask-codey.com/lessons/arrays-in-csharp-introduction-to-arrays