eslint/no-redeclare Pedantic

What it does

This rule disallows redeclaring variables within the same scope, ensuring that each variable is declared only once. It helps avoid confusion and unintended behavior in code.

Why is this bad?

Redeclaring variables in the same scope can lead to unexpected behavior, overwriting existing values, and making the code harder to understand and maintain.

Examples

Examples of incorrect code for this rule:

javascript

var a = 3;
var a = 10;

Examples of correct code for this rule:

javascript

var a = 3;
a = 10;

Configuration

This rule accepts a configuration object with the following properties:

builtinGlobals

type: boolean

default: true

When set true, it flags redeclaring built-in globals (e.g., let Object = 1;).

How to use

To enable this rule using the config file or in the CLI, you can use:

Config (.oxlintrc.json)Config (oxlint.config.ts)CLI

json

{
  "rules": {
    "no-redeclare": "error"
  }
}

import { defineConfig } from "oxlint";

export default defineConfig({
  rules: {
    "no-redeclare": "error",
  },
});

bash

oxlint --deny no-redeclare

Version

This rule was added in v0.0.13.

What it does ​

Why is this bad? ​

Examples ​

Configuration ​

builtinGlobals ​

How to use ​

Version ​

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