Require or disallow spaces before/after unary operators (space-unary-ops)

要求或禁止在一元操作符之前或之后存在空格 (space-unary-ops)

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

命令行中的 --fix 选项可以自动修复一些该规则报告的问题。

Some style guides require or disallow spaces before or after unary operators. This is mainly a stylistic issue, however, some JavaScript expressions can be written without spacing which makes it harder to read and maintain.

一些风格指南要求或禁止在一元操作符之前或之后存在空格。这主要是一个风格问题，然而，一些 JavaScript 表达式如果不写空格将会使其难以阅读和维护。

Rule Details

This rule enforces consistency regarding the spaces after words unary operators and after/before nonwords unary operators.

该规则强制 words 一元操作符后空格和 nonwords 一元操作符之前或之后的空格的一致性。

Examples of unary words operators:

一元 words 操作符的例子：

// new
var joe = new Person();

// delete
var obj = {
    foo: 'bar'
};
delete obj.foo;

// typeof
typeof {} // object

// void
void 0 // undefined

Examples of unary nonwords operators:

一元 nonwords 操作符的例子：

if ([1,2,3].indexOf(1) !== -1) {};
foo = --foo;
bar = bar++;
baz = !foo;
qux = !!baz;

Options

This rule has three options:

该规则有三个可选项：

• words - applies to unary word operators such as: new, delete, typeof, void, yield
• words - 适用于单词类一元操作符，例如：new、delete、typeof、void、yield
• nonwords - applies to unary operators such as: -, +, --, ++, !, !!
• nonwords - 适用于这些一元操作符: -、+、--、++、!、!!
• overrides - specifies overwriting usage of spacing for each operator, word or non word. This is empty by default, but can be used to enforce or disallow spacing around operators. For example:
• overrides - 覆盖操作符周围空格的用法。默认为空，但可用来强制或禁止操作符周围有空格。例如：

    "space-unary-ops": [
        2, {
          "words": true,
          "nonwords": false,
          "overrides": {
            "new": false,
            "++": true
          }
    }]

In this case, spacing will be disallowed after a new operator and required before/after a ++ operator.

在这个例子中，new 操作符之后禁用空格，++ 操作左右要求有空格。

Examples of incorrect code for this rule with the default {"words": true, "nonwords": false} option:

默认选项 {"words": true, "nonwords": false} 的 错误 代码示例：

/*eslint space-unary-ops: "error"*/

typeof!foo;

void{foo:0};

new[foo][0];

delete(foo.bar);

++ foo;

foo --;

- foo;

+ "3";

/*eslint space-unary-ops: "error"*/
/*eslint-env es6*/

function *foo() {
    yield(0)
}

/*eslint space-unary-ops: "error"*/

async function foo() {
    await(bar);
}

Examples of correct code for this rule with the {"words": true, "nonwords": false} option:

选项 {"words": true, "nonwords": false} 的 正确 代码示例：

/*eslint space-unary-ops: "error"*/

// Word unary operator "delete" is followed by a whitespace.
delete foo.bar;

// Word unary operator "new" is followed by a whitespace.
new Foo;

// Word unary operator "void" is followed by a whitespace.
void 0;

// Unary operator "++" is not followed by whitespace.
++foo;

// Unary operator "--" is not preceded by whitespace.
foo--;

// Unary operator "-" is not followed by whitespace.
-foo;

// Unary operator "+" is not followed by whitespace.
+"3";

/*eslint space-unary-ops: "error"*/
/*eslint-env es6*/

function *foo() {
    yield (0)
}

/*eslint space-unary-ops: "error"*/

async function foo() {
    await (bar);
}

Version

This rule was introduced in ESLint 0.10.0.

该规则在 ESLint 0.10.0 中被引入。

Resources

• Rule source
• Documentation source