> For the complete documentation index, see [llms.txt](https://docs.yarnspinner.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.yarnspinner.dev/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock.md).

# BasicBlock

Class in [Yarn.Compiler](/2.5/api/csharp/yarn.compiler.md)

Inherits from `System.Object`

## Summary

A basic block is a run of instructions inside a Node. Basic blocks group instructions up into segments such that execution only ever begins at the start of a block (that is, a program never jumps into the middle of a block), and execution only ever leaves at the end of a block.

```csharp
public class BasicBlock
```

## Classes

| Name                                                                                                                                          | Description                                                                 |
| --------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------- |
| [CommandElement](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.commandelement.md)                           | A command that will be executed.                                            |
| [LineElement](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.lineelement.md)                                 | A line of dialogue that should be shown to the player.                      |
| [OptionsElement](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.optionselement.md)                           | A collection of options that should be shown to the player.                 |
| [PlayerVisibleContentElement](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.playervisiblecontentelement.md) | An abstract class that represents some content that is shown to the player. |

## Enums

| Name                                                                                                      | Description                                                                                                                                                                           |
| --------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [Condition](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.condition.md) | The conditions under which a [Destination](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.destination.md) may be reached at the end of a BasicBlock. |

## Methods

| Name                                                                                                                                        | Description                                                         |
| ------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------- |
| [AddDestination(string,Condition)](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.adddestination-2.md)     | Adds a new destination to this block, that points to a node.        |
| [AddDestination(BasicBlock,Condition)](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.adddestination-1.md) | Adds a new destination to this block, that points to another block. |
| [ToString()](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.tostring.md)                                   |                                                                     |

## Properties

| Name                                                                                                                                                          | Description                                                                                                                                        |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- |
| [Ancestors](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.ancestors.md)                                                     | Get the ancestors of this block - that is, blocks that may run immediately before this block.                                                      |
| [Descendants](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.descendants.md)                                                 | Gets all descendants (that is, destinations, and destinations of those destinations, and so on), recursively.                                      |
| [DescendantsWithPlayerVisibleContent](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.descendantswithplayervisiblecontent.md) | Gets all descendants (that is, destinations, and destinations of those destinations, and so on) that have any player-visible content, recursively. |
| [Destinations](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.destinations.md)                                               | Gets the destinations of this block - that is, blocks or nodes that may run immediately after this block.                                          |
| [FirstInstructionIndex](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.firstinstructionindex.md)                             | Gets the index of the first instruction of the node that this block is in.                                                                         |
| [Instructions](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.instructions.md)                                               | Gets the Instructions that form this block.                                                                                                        |
| [LabelName](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.labelname.md)                                                     | Gets the name of the label that this block begins at, or null if this basic block does not begin at a labelled instruction.                        |
| [Name](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.name.md)                                                               | Gets a descriptive name for the block.                                                                                                             |
| [NodeName](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.nodename.md)                                                       | Gets the name of the node that this block is in.                                                                                                   |
| [PlayerVisibleContent](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.playervisiblecontent.md)                               | Gets the collection of player-visible content that will be delivered when this block is run.                                                       |

## Structs

| Name                                                                                                          | Description                                                                                                                                                                                                                        |
| ------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [Destination](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock/yarn.compiler.basicblock.destination.md) | A destination represents a [BasicBlock](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock.md) or node that may be run, following the execution of a [BasicBlock](/2.5/api/csharp/yarn.compiler/yarn.compiler.basicblock.md) . |