newline-after-var

Require or disallow an empty line after variable declarations

🔧

Some problems reported by this rule are automatically fixable by the --fix command line option

此规则在 ESLint v4.0.0 中废弃，并被 padding-line-between-statements 规则取代。

迄今为止，变量声明与代码其他部分的分离并不一致。有些开发者在 var 语句和其他代码之间留有空行，比如：

var foo;

// do something with foo
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而另一些人则根本不留任何空换行。

var foo;
// do something with foo
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问题是当这些开发人员在一个项目中一起工作时。这条规则强制执行一种编码风格，即允许或不允许在 var、let 或 const 语句后有空换行。它可以帮助代码在整个项目中看起来一致。

规则细节

这条规则强制执行一种编码风格，即在 var、let 或 const 语句后需要或不允许有空行，以实现整个项目的统一编码风格。

选项

此规则选项为字符串：

"always"（默认值）要求在 var、let 或 const 后面有空行。

在 var 语句后面的注释被视为额外的 var 语句。
"never" 不允许在 var、let 或 const 后面空行。

always

使用此规则与默认的 "always" 选项的错误示例：

Open in Playground

/*eslint newline-after-var: ["error", "always"]*/
/*eslint-env es6*/

var greet = "hello,",
    name = "world";
console.log(greet, name);

let greet = "hello,",
    name = "world";
console.log(greet, name);

var greet = "hello,";
const NAME = "world";
console.log(greet, NAME);

var greet = "hello,";
var name = "world";
// var name = require("world");
console.log(greet, name);
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使用此规则与默认的 "always" 选项的正确示例：

Open in Playground

/*eslint newline-after-var: ["error", "always"]*/
/*eslint-env es6*/

var greet = "hello,",
    name = "world";

console.log(greet, name);

let greet = "hello,",
    name = "world";

console.log(greet, name);

var greet = "hello,";
const NAME = "world";

console.log(greet, NAME);

var greet = "hello,";
var name = "world";
// var name = require("world");

console.log(greet, name);
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never

使用此规则与 "never" 选项的错误示例：

Open in Playground

/*eslint newline-after-var: ["error", "never"]*/
/*eslint-env es6*/

var greet = "hello,",
    name = "world";

console.log(greet, name);

let greet = "hello,",
    name = "world";

console.log(greet, name);

var greet = "hello,";
const NAME = "world";

console.log(greet, NAME);

var greet = "hello,";
var name = "world";
// var name = require("world");

console.log(greet, name);
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使用此规则与 "never" 选项的正确示例：

Open in Playground

/*eslint newline-after-var: ["error", "never"]*/
/*eslint-env es6*/

var greet = "hello,",
    name = "world";
console.log(greet, name);

let greet = "hello,",
    name = "world";
console.log(greet, name);

var greet = "hello,";
const NAME = "world";
console.log(greet, NAME);

var greet = "hello,";
var name = "world";
// var name = require("world");
console.log(greet, name);
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Version

This rule was introduced in ESLint v0.18.0.

Resources

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