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Enforce default parameters to be last (default-param-last)

Rule Details

This rule extends the base eslint/default-param-last rule. It adds support for optional parameters.

/* eslint @typescript-eslint/default-param-last: ["error"] */

function f(a = 0, b: number) {}
function f(a: number, b = 0, c: number) {}
function f(a: number, b?: number, c: number) {}
class Foo {
constructor(public a = 10, private b: number) {}
class Foo {
constructor(public a?: number, private b: number) {}

How to Use

// note you must disable the base rule as it can report incorrect errors
"default-param-last": "off",
"@typescript-eslint/default-param-last": ["error"]


See eslint/default-param-last options.

Taken with โค๏ธ from ESLint core


  • โœ… Recommended
  • ๐Ÿ”ง Fixable
  • ๐Ÿ’ญ Requires type information