# Disallow multiple spaces (no-multi-spaces)

Multiple spaces in a row that are not used for indentation are typically mistakes. For example:

```js

if(foo  === "bar") {}

```

It's hard to tell, but there are two spaces between `foo` and `===`. Multiple spaces such as this are generally frowned upon in favor of single spaces:

```js

if(foo === "bar") {}

```

## Rule Details

This rule aims to disallow multiple whitespace around logical expressions, conditional expressions, declarations, array elements, object properties, sequences and function parameters.

Examples of **incorrect** code for this rule:

```js
/*eslint no-multi-spaces: "error"*/

var a =  1;

if(foo   === "bar") {}

a <<  b

var arr = [1,  2];

a ?  b: c
```

Examples of **correct** code for this rule:

```js
/*eslint no-multi-spaces: "error"*/

var a = 1;

if(foo === "bar") {}

a << b

var arr = [1, 2];

a ? b: c
```

## Options

This rule's configuration consists of an object with the following properties:

* `"ignoreEOLComments": true` (defaults to `false`) ignores multiple spaces before comments that occur at the end of lines
* `"exceptions": { "Property": true }` (`"Property"` is the only node specified by default) specifies nodes to ignore

### ignoreEOLComments

Examples of **incorrect** code for this rule with the `{ "ignoreEOLComments": false }` (default) option:

```js
/*eslint no-multi-spaces: ["error", { ignoreEOLComments: false }]*/

var x = 5;      // comment
var x = 5;      /* multiline
 * comment
 */
```

Examples of **correct** code for this rule with the `{ "ignoreEOLComments": false }` (default) option:

```js
/*eslint no-multi-spaces: ["error", { ignoreEOLComments: false }]*/

var x = 5; // comment
var x = 5; /* multiline
 * comment
 */
```

Examples of **correct** code for this rule with the `{ "ignoreEOLComments": true }` option:

```js
/*eslint no-multi-spaces: ["error", { ignoreEOLComments: true }]*/

var x = 5; // comment
var x = 5;      // comment
var x = 5; /* multiline
 * comment
 */
var x = 5;      /* multiline
 * comment
 */
```

### exceptions

To avoid contradictions with other rules that require multiple spaces, this rule has an `exceptions` option to ignore certain nodes.

This option is an object that expects property names to be AST node types as defined by [ESTree](https://github.com/estree/estree). The easiest way to determine the node types for `exceptions` is to use [AST Explorer](https://astexplorer.net/) with the espree parser.

Only the `Property` node type is ignored by default, because for the [key-spacing](key-spacing.md) rule some alignment options require multiple spaces in properties of object literals.

Examples of **correct** code for the default `"exceptions": { "Property": true }` option:

```js
/*eslint no-multi-spaces: "error"*/
/*eslint key-spacing: ["error", { align: "value" }]*/

var obj = {
    first:  "first",
    second: "second"
};
```

Examples of **incorrect** code for the `"exceptions": { "Property": false }` option:

```js
/*eslint no-multi-spaces: ["error", { exceptions: { "Property": false } }]*/
/*eslint key-spacing: ["error", { align: "value" }]*/

var obj = {
    first:  "first",
    second: "second"
};
```

Examples of **correct** code for the `"exceptions": { "BinaryExpression": true }` option:

```js
/*eslint no-multi-spaces: ["error", { exceptions: { "BinaryExpression": true } }]*/

var a = 1  *  2;
```

Examples of **correct** code for the `"exceptions": { "VariableDeclarator": true }` option:

```js
/*eslint no-multi-spaces: ["error", { exceptions: { "VariableDeclarator": true } }]*/

var someVar      = 'foo';
var someOtherVar = 'barBaz';
```

Examples of **correct** code for the `"exceptions": { "ImportDeclaration": true }` option:

```js
/*eslint no-multi-spaces: ["error", { exceptions: { "ImportDeclaration": true } }]*/

import mod          from 'mod';
import someOtherMod from 'some-other-mod';
```

## When Not To Use It

If you don't want to check and disallow multiple spaces, then you should turn this rule off.

## Related Rules

* [key-spacing](key-spacing.md)
* [space-infix-ops](space-infix-ops.md)
* [space-in-brackets](space-in-brackets.md) (deprecated)
* [space-in-parens](space-in-parens.md)
* [space-after-keywords](space-after-keywords.md)
* [space-unary-ops](space-unary-ops.md)
* [space-return-throw-case](space-return-throw-case.md)