comma-spacing
Enforce consistent spacing before and after commas
đ§ Fixable
Some problems reported by this rule are automatically fixable by the --fix command line option
This rule was deprecated in ESLint v8.53.0. Please use the corresponding rule in @stylistic/eslint-plugin-js.
Spacing around commas improves readability of a list of items. Although most of the style guidelines for languages prescribe adding a space after a comma and not before it, it is subjective to the preferences of a project.
var foo = 1, bar = 2;
var foo = 1 ,bar = 2;
Rule Details
This rule enforces consistent spacing before and after commas in variable declarations, array literals, object literals, function parameters, and sequences.
This rule does not apply in either of the following cases:
- between two commas
- between opening bracket
[and comma, to avoid conflicts with thearray-bracket-spacingrule - between comma and closing bracket
], to avoid conflicts with thearray-bracket-spacingrule - between comma and closing brace
}, to avoid conflicts with theobject-curly-spacingrule - between comma and closing parentheses
), to avoid conflicts with thespace-in-parensrule
Options
This rule has an object option:
"before": false(default) disallows spaces before commas"before": truerequires one or more spaces before commas"after": true(default) requires one or more spaces after commas"after": falsedisallows spaces after commas
after
Examples of incorrect code for this rule with the default { "before": false, "after": true } options:
Open in Playground
/*eslint comma-spacing: ["error", { "before": false, "after": true }]*/
var foo = 1 ,bar = 2;
var arr = [1 , 2];
var obj = {"foo": "bar" ,"baz": "qur"};
foo(a ,b);
new Foo(a ,b);
function baz(a ,b){}
a ,b
Examples of correct code for this rule with the default { "before": false, "after": true } options:
Open in Playground
/*eslint comma-spacing: ["error", { "before": false, "after": true }]*/
var foo = 1, bar = 2
, baz = 3;
var arr = [1, 2];
var arr = [1,, 3]
var obj = {"foo": "bar", "baz": "qur"};
foo(a, b);
new Foo(a, b);
function qur(a, b){}
a, b
Additional examples of correct code for this rule with the default { "before": false, "after": true } options:
Open in Playground
/*eslint comma-spacing: ["error", { "before": false, "after": true }]*/
// this rule does not enforce spacing between two commas
var arr = [
,,
, ,
];
// this rule does not enforce spacing after `[` and before `]`
var arr = [,];
var arr = [ , ];
var arr = [a, b,];
[,] = arr;
[ , ] = arr;
[a, b,] = arr;
// this rule does not enforce spacing before `}`
var obj = {x, y,};
var {z, q,} = obj;
import {foo, bar,} from "mod";
// this rule does not enforce spacing before `)`
foo(a, b,)
before
Examples of incorrect code for this rule with the { "before": true, "after": false } options:
Open in Playground
/*eslint comma-spacing: ["error", { "before": true, "after": false }]*/
var foo = 1, bar = 2;
var arr = [1 , 2];
var obj = {"foo": "bar", "baz": "qur"};
new Foo(a,b);
function baz(a,b){}
a, b
Examples of correct code for this rule with the { "before": true, "after": false } options:
Open in Playground
/*eslint comma-spacing: ["error", { "before": true, "after": false }]*/
var foo = 1 ,bar = 2 ,
baz = true;
var arr = [1 ,2];
var arr = [1 ,,3]
var obj = {"foo": "bar" ,"baz": "qur"};
foo(a ,b);
new Foo(a ,b);
function qur(a ,b){}
a ,b
When Not To Use It
If your project will not be following a consistent comma-spacing pattern, turn this rule off.
Related Rules
Version
This rule was introduced in ESLint v0.9.0.
Further Reading
