# Disable TypeScript 'declared but never read' check

> Fix the TypeScript error 'declared but its value is never read' by setting noUnusedLocals to false in tsconfig.json, plus noUnusedParameters for parameters.

Author: Flavio Copes | Published: 2021-07-05 | Canonical: https://flaviocopes.com/typescript-disable-declared-never-read/

If you declare a variable but never use it, [TypeScript](https://flaviocopes.com/typescript) will not compile, saying `'<variable>' is declared but its value is never read`.

That error will not go away until you use that variable somewhere.

If this happens on a single line, you can use the line `// @ts-ignore` before the problematic line, but like in this case it'd be useless because the error would happen again immediately in the second line.

You can disable this error check globally by opening the `tsconfig.json` file and setting the `noUnusedLocals` property to `false`.

Once you do, restart `yarn start` in order to pick up the new setting.

There's also `noUnusedParameters` to do the same for unused function parameters. Leave it to `true` now.

One thing I recommend is to do that now that we're in "building mode", but then re-enable those checks as soon as your code is starting to finalize, because they can really help make your code better.