eslint/docs/rules/max-params.md

   1 # enforce a maximum number of parameters in function definitions (max-params)
   2
   3 Functions that take numerous parameters can be difficult to read and write because it requires the memorization of what each parameter is, its type, and the order they should appear in. As a result, many coders adhere to a convention that caps the number of parameters a function can take.
   4
   5 ```js
   6 function foo (bar, baz, qux, qxx) { // four parameters, may be too many
   7     doSomething();
   8 }
   9 ```
  10
  11 ## Rule Details
  12
  13 This rule enforces a maximum number of parameters allowed in function definitions.
  14
  15 ## Options
  16
  17 This rule has a number or object option:
  18
  19 * `"max"` (default `3`) enforces a maximum number of parameters in function definitions
  20
  21 **Deprecated:** The object property `maximum` is deprecated; please use the object property `max` instead.
  22
  23 ### max
  24
  25 Examples of **incorrect** code for this rule with the default `{ "max": 3 }` option:
  26
  27 ```js
  28 /*eslint max-params: ["error", 3]*/
  29 /*eslint-env es6*/
  30
  31 function foo (bar, baz, qux, qxx) {
  32     doSomething();
  33 }
  34
  35 let foo = (bar, baz, qux, qxx) => {
  36     doSomething();
  37 };
  38 ```
  39
  40 Examples of **correct** code for this rule with the default `{ "max": 3 }` option:
  41
  42 ```js
  43 /*eslint max-params: ["error", 3]*/
  44 /*eslint-env es6*/
  45
  46 function foo (bar, baz, qux) {
  47     doSomething();
  48 }
  49
  50 let foo = (bar, baz, qux) => {
  51     doSomething();
  52 };
  53 ```
  54
  55 ## Related Rules
  56
  57 * [complexity](complexity.md)
  58 * [max-depth](max-depth.md)
  59 * [max-len](max-len.md)
  60 * [max-lines](max-lines.md)
  61 * [max-lines-per-function](max-lines-per-function.md)
  62 * [max-nested-callbacks](max-nested-callbacks.md)
  63 * [max-statements](max-statements.md)