# TS6133: '…' is declared but its value is never read.

> A local variable, import, parameter or private member is declared but never read. Remove it, or prefix an unused parameter with `_`.

## What it means

Reported when `noUnusedLocals` (for variables, imports, functions and private members) or
`noUnusedParameters` (for parameters) is on. Something is declared but its value is never
read. Assigning to it doesn't count as reading it. Editors show these declarations faded.

## Example

```json
{ "compilerOptions": { "noUnusedLocals": true } }
```

```ts
export function total(prices: number[]): number {
  const tax = 0.1;
  return prices.reduce((a, b) => a + b, 0);
}
```

## How to fix

- Delete the unused declaration or import.
- For a parameter you must keep (for example a callback signature), name it with a leading
  underscore: `_event`.
- For destructuring where you only want the rest, `const { id: _id, ...rest } = obj` keeps it
  quiet.

Source: https://ts-r.dev/errors/TS6133/