# Boolean: true or false

[Syntax and values](README.md)

A Boolean answers a yes-or-no question. It is useful for remembering whether a door is open or deciding whether a score is high enough.

## Behavior and details

Boolean has exactly two values, true and false. if, while, and, or, not, GPIO writes, sprite flips, and 3D solidity require actual Booleans. Numeric and text values are not automatically converted. Comparison operators and the yes/no input function return Booleans.

## Example

```pliro
# language: en
let ready = 3 < 5
say ready, not ready
```

## Related entries

[Syntax and values](README.md) · [Built-ins](../builtins/README.md) · [Programming guides](../guides/README.md)