eslint/docs/src/rules/default-param-last.md

   1 ---
   2 title: default-param-last
   3 layout: doc
   4 rule_type: suggestion
   5 ---
   6
   7 Putting default parameter at last allows function calls to omit optional tail arguments.
   8
   9 ```js
  10 // Correct: optional argument can be omitted
  11 function createUser(id, isAdmin = false) {}
  12 createUser("tabby")
  13
  14 // Incorrect: optional argument can **not** be omitted
  15 function createUser(isAdmin = false, id) {}
  16 createUser(undefined, "tabby")
  17 ```
  18
  19 ## Rule Details
  20
  21 This rule enforces default parameters to be the last of parameters.
  22
  23 Examples of **incorrect** code for this rule:
  24
  25 ::: incorrect
  26
  27 ```js
  28 /* eslint default-param-last: ["error"] */
  29
  30 function f(a = 0, b) {}
  31
  32 function f(a, b = 0, c) {}
  33 ```
  34
  35 :::
  36
  37 Examples of **correct** code for this rule:
  38
  39 ::: correct
  40
  41 ```js
  42 /* eslint default-param-last: ["error"] */
  43
  44 function f(a, b = 0) {}
  45 ```
  46
  47 :::