# AndAll

`type` in `services` · v0.8.2

<https://docs.seedcord.org/packages/services/0.8.2/types/and-all>

Returns a boolean for whether all of the given elements are `true`.

Use-cases: - Check if all conditions in a list of booleans are met.

## Examples

```ts
import type {AndAll} from 'type-fest';

type TTT = AndAll<[true, true, true]>;
//=> true

type TTF = AndAll<[true, true, false]>;
//=> false

type TFT = AndAll<[true, false, true]>;
//=> false

Note: When boolean is passed as an element, it is distributed into separate cases, and the final result is a union of those cases. For example, AndAll<[true, boolean]> expands to AndAll<[true, true]> | AndAll<[true, false]>, which simplifies to true | false (i.e., boolean).
```

```ts
import type {AndAll} from 'type-fest';

type A = AndAll<[true, boolean]>;
//=> boolean

type B = AndAll<[false, boolean]>;
//=> false

Note: If any of the elements is never, the result becomes false.
```

```ts
import type {AndAll} from 'type-fest';

type A = AndAll<[true, true, never]>;
//=> false

type B = AndAll<[false, never, never]>;
//=> false

type C = AndAll<[never, never, never]>;
//=> false

type D = AndAll<[boolean, true, never]>;
//=> false

Note: If any is passed as an element, it is treated as boolean and the result is computed accordingly.
```

```ts
import type {AndAll} from 'type-fest';

type A = AndAll<[false, any]>;
//=> false

type B = AndAll<[true, any]>;
//=> boolean

Note: AndAll<[]> evaluates to true due to the concept of [vacuous truth](https://en.wikipedia.org/wiki/Logical_conjunction#:~:text=In%20keeping%20with%20the%20concept%20of%20vacuous%20truth%2C%20when%20conjunction%20is%20defined%20as%20an%20operator%20or%20function%20of%20arbitrary%20arity%2C%20the%20empty%20conjunction%20(AND%2Ding%20over%20an%20empty%20set%20of%20operands)%20is%20often%20defined%20as%20having%20the%20result%20true.), i.e., there are no false elements in an empty tuple.
```

## Declaration

```ts
type AndAll<T extends readonly boolean[]> = AllExtend<T, true>;
```

## See also

- [And](/packages/services/0.8.2/types/and)
- [OrAll](/packages/services/0.8.2/types/or-all)