one-var-declaration-per-line

The --fix option on the command line can automatically fix some of the problems reported by this rule.

Requires or disallows newlines around variable declarations.

Some developers declare multiple var statements on the same line:

var foo, bar, baz;

Others prefer to declare one var per line.

var foo,
    bar,
    baz;

Keeping to one of these styles across a project's codebase can help with maintaining code consistency.

Rule Details

This rule enforces a consistent newlines around variable declarations. This rule ignores variable declarations inside for loop conditionals.

This rule has a single string option:

"initializations" (default) enforces a newline around variable initializations
"always" enforces a newline around variable declarations

Examples of incorrect code for this rule with the default "initializations" option:

/*eslint one-var-declaration-per-line: ["error", "initializations"]*/
/*eslint-env es6*/

var a, b, c = 0;

let a,
    b = 0, c;

Examples of correct code for this rule with the default "initializations" option:

/*eslint one-var-declaration-per-line: ["error", "initializations"]*/
/*eslint-env es6*/

var a, b;

let a,
    b;

let a,
    b = 0;

Examples of incorrect code for this rule with the "always" option:

/*eslint one-var-declaration-per-line: ["error", "always"]*/
/*eslint-env es6*/

var a, b;

let a, b = 0;

const a = 0, b = 0;

Examples of correct code for this rule with the "always" option:

/*eslint one-var-declaration-per-line: ["error", "always"]*/
/*eslint-env es6*/

var a,
    b;

let a,
    b = 0;

This rule was introduced in ESLint 2.0.0-beta.3.