# Switch Expressions and the Conditional Operator

Choose a value, rather than run a block, with C#'s conditional operator for two choices and a switch expression for many.

Apprentice · C# · Updated November 3, 2026

## After this lesson you can

- Choose one of two values with the conditional operator ?:
- Turn a value into a result with a switch expression

## Key takeaways

- The conditional operator picks one of two values. `isThree ? 3 : 2` is 3 when `isThree` is `true`, otherwise 2.
- A switch expression turns one value into another. Each arm is a pattern, `=>` and a result, and the arms are separated by commas.
- In a switch expression, `or` lets one arm match several values, and `_` matches anything, so it goes last.
- Arms can compare with `<`, `>`, `<=` and `>=` and join them with `and`. C# uses the first arm that matches.
- To run different code, use `if` or a `switch` statement; to pick a value, use `?:` or a switch expression.

Often a decision exists only to pick a **value**: the price, the label, the message. An `if` statement or a `switch` statement can do it, but you have to declare a variable first and set it in every branch. C# has two shorter ways that produce the value directly.

## Two choices: the conditional operator

The **conditional operator** `?:` picks one of two values:

```csharp
// condition ? valueIfTrue : valueIfFalse
bool isThree = true;

int pointsPerShot = isThree ? 3 : 2;
Console.WriteLine(pointsPerShot);
```

```text
3
```

Read it as a question: *is it a three-pointer? Then 3, otherwise 2.* It does the same job as this `if-else`, in one line:

```csharp
bool isThree = true;
int pointsPerShot;

if (isThree)
{
    pointsPerShot = 3;
}
else
{
    pointsPerShot = 2;
}

Console.WriteLine(pointsPerShot);
```

```text
3
```

It's also called the **ternary operator**, because it has three parts. Keep it for simple choices; when either side needs more than a value, an `if` reads better.

## Many choices: switch expressions

A **switch expression** turns one value into another. The variable comes first, then `switch`, then one **arm** per case: a pattern, `=>`, and the result.

```csharp
string dayOfTheWeek = "Tuesday";

string dinner = dayOfTheWeek switch
{
    "Monday" => "Soup and sandwiches",
    "Tuesday" => "Tacos",
    "Wednesday" => "Sushi",
    "Saturday" or "Sunday" => "Somewhere new",
    _ => "Pasta"
};

Console.WriteLine(dinner);
```

```text
Tacos
```

- The arms are separated by commas, and the whole expression ends with `};`.
- `or` lets one arm match several values.
- `_` is the **discard** pattern: it matches anything, like `default` in a switch statement. Put it last.
- There's no `break`: each arm is a value, not a block of code.

## Matching ranges

A switch expression can also compare with `<`, `>`, `<=` and `>=`, and join comparisons with `and`. This is **pattern matching**. C# checks the arms from the top and uses the first one that matches:

```csharp
Console.WriteLine(LetterGrade(93));
Console.WriteLine(LetterGrade(85));
Console.WriteLine(LetterGrade(61));

string LetterGrade(int score) => score switch
{
    >= 90 => "A",
    >= 80 and < 90 => "B",
    >= 70 => "C",
    >= 60 => "D",
    _ => "F"
};
```

```text
A
B
D
```

`string LetterGrade(int score) => ...` is a method whose body is a single expression. The `=>` replaces `{ return ...; }`. It's handy when a method's whole job is one expression, as it is here.

## Which one to use

| You want to | Use |
|---|---|
| Run different **code** for different conditions | `if` / `else if` / `else`, or a `switch` statement |
| Pick one of **two values** | the conditional operator `?:` |
| Turn one value into another, with **many** cases | a switch expression |

## Check yourself

2 questions to try on the lesson page.

## So what

When a decision's only job is to choose a value, `?:` and switch expressions let you say so directly, in fewer lines, with no variable left unset by a forgotten branch.

## Key terms

- [Ternary Operator](https://www.ask-codey.com/glossary/ternary-operator-c-style)
- [switch Expression](https://www.ask-codey.com/glossary/switch-expression)
- [Pattern Matching](https://www.ask-codey.com/glossary/pattern-matching)

## Cheat sheets

- [Switch Expressions and the Conditional Operator](https://www.ask-codey.com/cheat-sheets/conditional-logic-in-csharp-switch-expressions-cheat-sheet)

Source: https://www.ask-codey.com/lessons/conditional-logic-in-csharp-switch-expressions