[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [Function](https://evolu.dev/docs/api-reference/common/Function) › identity

```ts
function identity<A>(a: A): A;
```

Defined in: [packages/common/src/Function.ts:109](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/Function.ts#L109)

Returns the value unchanged.

Useful as a default transformation, placeholder callback, or when a function
is required but no transformation is needed.

### Example

```ts
const values = [1, 2, 3];
const same = values.map(identity); // [1, 2, 3]

const getTransform = (shouldDouble: boolean) =>
  shouldDouble ? (x: number) => x * 2 : identity;
```