# none

Source: https://taxilang.org/docs/language/stdlib/none

**Full name:** `taxi.stdlib.none`

## Signature

```taxi
declare extension function <T> none(collection: T[], predicate: (T) -> Boolean): Boolean
```

## Description

Returns `true` if none of the items in the collection satisfy the predicate.

Returns `true` for an empty collection (vacuous truth).

```taxi
// Check that no task is overdue
find { sprint: Sprint } as {
   noOverdue: Boolean = sprint.tasks.none((task) -> task.isOverdue)
}
```

## Examples

Returns `true` when no item in the collection satisfies the predicate.

Schema:

```taxi
model Task {
   name: String
   isComplete: Boolean
}
```

Query:

```taxi
given {
   tasks: Task[] = [
      { name: 'Setup', isComplete: true },
      { name: 'Build', isComplete: true },
      { name: 'Deploy', isComplete: true }
   ]
}
find {
   noneIncomplete: Boolean = tasks.none((task: Task) -> task.isComplete == false)
}
```

Result:

```json
{
  "noneIncomplete": true
}
```