# If

Run code only when a condition is true, with if, if-else and else if, and write conditions with C#'s comparison operators.

Novice · C# · Updated November 3, 2026

## After this lesson you can

- Choose between actions with if, else if and else
- Compare two values with C#'s comparison operators

## Key takeaways

- A condition is a `bool`. The comparison operators `==`, `!=`, `>`, `<`, `>=` and `<=` compare two values and give `true` or `false`.
- `==` asks whether two values are equal; a single `=` puts a value into a variable.
- `if` runs its block only when the condition is `true`, and `if-else` runs exactly one of its two blocks.
- With `else if`, C# runs the first block whose condition is `true` and skips the rest, so put the most demanding condition first.

Every programming language lets you run code only when a condition is met. Making decisions is what programming logic is all about: *if* the cart is empty, show a message; *if* the password is wrong, ask again.

## Conditions are true or false

A **condition** is an expression whose value is a `bool`: `true` or `false`. You build most conditions by comparing two values:

| Operator | Means | Example | Value |
|---|---|---|---|
| `==` | is equal to | `5 == 5` | `true` |
| `!=` | is not equal to | `5 != 3` | `true` |
| `>` | is greater than | `20 > 10` | `true` |
| `<` | is less than | `20 < 10` | `false` |
| `>=` | is greater than or equal to | `10 >= 10` | `true` |
| `<=` | is less than or equal to | `9 <= 8` | `false` |

Notice that "is equal to" is two equals signs. A single `=` puts a value into a variable; `==` asks whether two values are the same.

```csharp
int availableCash = 20;
Console.WriteLine(availableCash > 10);
Console.WriteLine(availableCash == 15);
```

```text
True
False
```

## if

An `if` statement runs a block of code only when its condition is `true`. When it's `false`, the block is skipped.

![A flowchart: if the condition is true, run the block; either way, carry on](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/11/3c802a4749014ee5b7dd8221e1ed9343.webp)

```csharp
int availableCash = 20;

if (availableCash > 10)
{
    Console.WriteLine("You can eat out tonight.");
}

Console.WriteLine("Time to decide.");
```

```text
You can eat out tonight.
Time to decide.
```

The condition goes in parentheses, and the code to run goes in curly braces. The line after the `if` runs either way.

## if-else

An `if-else` statement has two blocks, and exactly one of them runs.

![A flowchart: if the condition is true run the first block, otherwise run the second](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/11/9cdfe455e38643a38945a7c652c18f9d.webp)

```csharp
int availableCash = 15;

if (availableCash > 20)
{
    Console.WriteLine("Let's get pizza.");
}
else
{
    Console.WriteLine("Let's get tacos.");
}
```

```text
Let's get tacos.
```

## else if

When there are more than two choices, add `else if` blocks between them. C# checks each condition from the top and runs the **first** block whose condition is `true`, then skips the rest. The `else` at the end runs only if none of them was true.

![A flowchart with three branches: the first true condition wins, else is the fallback](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/11/65b17af2c719448eaa6be179e4741cea.webp)

```csharp
int availableCash = 35;

if (availableCash > 50)
{
    Console.WriteLine("Let's go to the steakhouse.");
}
else if (availableCash > 20)
{
    Console.WriteLine("Let's get pizza.");
}
else
{
    Console.WriteLine("Let's get tacos.");
}
```

```text
Let's get pizza.
```

Order matters. With $60, both `60 > 50` and `60 > 20` are true, but only the first true branch runs: steakhouse. If `> 20` came first, $60 would get pizza. Put the most demanding condition first.

## if in a method

Conditions are often what a method decides. This one returns a different value for different inputs:

```csharp
Console.WriteLine(GetShippingCost(45.00m));
Console.WriteLine(GetShippingCost(75.00m));

decimal GetShippingCost(decimal orderTotal)
{
    if (orderTotal >= 50)
    {
        return 0;
    }
    else
    {
        return 5.99m;
    }
}
```

```text
5.99
0
```

## Check yourself

2 questions to try on the lesson page.

## So what

With `if`, `else if` and `else`, your program stops doing the same thing every time and starts reacting to its data, which is where most of the interesting work in programming happens.

## Key terms

- [If-Else Statement](https://www.ask-codey.com/glossary/if-else-statement-c-style)
- [else if Statement](https://www.ask-codey.com/glossary/else-if-statement-c-sharp)
- [Comparison Operators](https://www.ask-codey.com/glossary/comparison-operators-c-sharp)

## Cheat sheets

- [If](https://www.ask-codey.com/cheat-sheets/conditional-logic-in-csharp-if-cheat-sheet)

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