Rule: no-duplicate-variable

Disallows duplicate variable declarations in the same block scope.

This rule is only useful when using the var keyword - the compiler will detect redeclarations of let and const variables.

Rationale

A variable can be reassigned if necessary - there’s no good reason to have a duplicate variable declaration.

Config

You can specify "check-parameters" to check for variables with the same name as a parameter.

Config examples

"no-duplicate-variable": true

"no-duplicate-variable": [true, "check-parameters"]

Schema

{
  "type": "string",
  "enum": [
    "check-parameters"
  ]
}