src/content/docs/linter/rules/no-unassigned-variables.mdx
import { Tabs, TabItem } from '@astrojs/starlight/components';
<Tabs> <TabItem label="JavaScript (and super languages)" icon="seti:javascript"> ## Summary - Rule available since: `v2.1.0` - Diagnostic Category: [`lint/suspicious/noUnassignedVariables`](/reference/diagnostics#diagnostic-category) - This rule isn't recommended, so you need to enable it. - This rule doesn't have a fix. - The default severity of this rule is [**information**](/reference/diagnostics#information). - Sources: - Same as [`no-unassigned-vars`](https://eslint.org/docs/latest/rules/no-unassigned-vars){
"linter": {
"rules": {
"suspicious": {
"noUnassignedVariables": "error"
}
}
}
}
Disallow let or var variables that are read but never assigned.
This rule flags let or var declarations that are never assigned a value but are still read or used in the code. Since these variables will always be undefined, their usage is likely a programming mistake.
let status;
if (status === 'ready') {
console.log('Status is ready');
}
let value: number | undefined;
console.log(value);
let message = "hello";
console.log(message);
let user;
user = getUser();
console.log(user.name);
let count;
count = 0;
count++;
declare let value: number | undefined;
console.log(value);
declare module "my-module" {
let value: string;
export = value;
}