one-var-declaration-per-line

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.

Options

This rule has a single string option:

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

initializations

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

::: incorrect

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

var a, b, c = 0;

let d,
    e = 0, f;

:::

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

::: correct

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

var a, b;

let c,
    d;

let e,
    f = 0;

:::

always

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

::: incorrect

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

var a, b;

let c, d = 0;

const e = 0, f = 0;

:::

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

::: correct

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

var a,
    b;

let c,
    d = 0;

:::