Require CamelCase (camelcase)

要求使用骆驼拼写法 (camelcase)

When it comes to naming variables, style guides generally fall into one of two camps: camelcase (variableName) and underscores (variable_name). This rule focuses on using the camelcase approach. If your style guide calls for camelCasing your variable names, then this rule is for you!

当命名变量时，风格指南一般会分为骆驼拼写法 (variableName) 和下划线拼写法 (variable_name) 两大阵营。该规则主要关注骆驼拼写法的用法。如果你的风格指南要求变量名称以驼峰的形式书写，此规则正适合于你。

Rule Details

This rule looks for any underscores (_) located within the source code. It ignores leading and trailing underscores and only checks those in the middle of a variable name. If ESLint decides that the variable is a constant (all uppercase), then no warning will be thrown. Otherwise, a warning will be thrown. This rule only flags definitions and assignments but not function calls. In case of ES6 import statements, this rule only targets the name of the variable that will be imported into the local module scope.

此规则在源码中查找下划线 (_)。它忽略前导和尾部的下划线，只检查在变量名称中间的下划线。如果 ESLint 判断定某个变量是个常量（全部大写），将不会发出警告。否则会发出警告。该规则仅仅标记定义和赋值，不适用于方法调用。在 ES6 import 语句中，该规则只针对将引入到本地模块作用域的变量名。

Options

This rule has an object option:

该规则有一个对象选项：

properties: “always”

Examples of incorrect code for this rule with the default { "properties": "always" } option:

默认选项 { "properties": "always" } 的 错误 代码示例：

/*eslint camelcase: "error"*/

import { no_camelcased } from "external-module"

var my_favorite_color = "#112C85";

function do_something() {
    // ...
}

obj.do_something = function() {
    // ...
};

function foo({ no_camelcased }) {
    // ...
};

function foo({ isCamelcased: no_camelcased }) {
    // ...
}

function foo({ no_camelcased = 'default value' }) {
    // ...
};

var obj = {
    my_pref: 1
};

var { category_id = 1 } = query;

var { foo: no_camelcased } = bar;

var { foo: bar_baz = 1 } = quz;

Examples of correct code for this rule with the default { "properties": "always" } option:

默认选项 { "properties": "always" } 的 正确 代码示例：

/*eslint camelcase: "error"*/

import { no_camelcased as camelCased } from "external-module";

var myFavoriteColor   = "#112C85";
var _myFavoriteColor  = "#112C85";
var myFavoriteColor_  = "#112C85";
var MY_FAVORITE_COLOR = "#112C85";
var foo = bar.baz_boom;
var foo = { qux: bar.baz_boom };

obj.do_something();
do_something();
new do_something();

var { category_id: category } = query;

function foo({ isCamelCased }) {
    // ...
};

function foo({ isCamelCased: isAlsoCamelCased }) {
    // ...
}

function foo({ isCamelCased = 'default value' }) {
    // ...
};

var { categoryId = 1 } = query;

var { foo: isCamelCased } = bar;

var { foo: isCamelCased = 1 } = quz;

properties: “never”

Examples of correct code for this rule with the { "properties": "never" } option:

选项 { "properties": "never" } 的 正确 代码示例：

/*eslint camelcase: ["error", {properties: "never"}]*/

var obj = {
    my_pref: 1
};

ignoreDestructuring: false

Examples of incorrect code for this rule with the default { "ignoreDestructuring": false } option:

选项 { "ignoreDestructuring": false } 的 错误 代码示例：

/*eslint camelcase: "error"*/

var { category_id } = query;

var { category_id = 1 } = query;

var { category_id: category_id } = query;

var { category_id: category_alias } = query;

var { category_id: categoryId, ...other_props } = query;

ignoreDestructuring: true

Examples of incorrect code for this rule with the { "ignoreDestructuring": true } option:

选项 { "ignoreDestructuring": true } 的 错误 代码示例：

/*eslint camelcase: ["error", {ignoreDestructuring: true}]*/

var { category_id: category_alias } = query;

var { category_id, ...other_props } = query;

Examples of correct code for this rule with the { "ignoreDestructuring": true } option:

选项 { "ignoreDestructuring": true } 的 正确 代码示例：

/*eslint camelcase: ["error", {ignoreDestructuring: true}]*/

var { category_id } = query;

var { category_id = 1 } = query;

var { category_id: category_id } = query;

allow

Examples of correct code for this rule with the allow option:

选项 allow 的 正确 代码示例：

/*eslint camelcase: ["error", {allow: ["UNSAFE_componentWillMount"]}]*/

function UNSAFE_componentWillMount() {
    // ...
}

/*eslint camelcase: ["error", {allow: ["^UNSAFE_"]}]*/

function UNSAFE_componentWillMount() {
    // ...
}

function UNSAFE_componentWillMount() {
    // ...
}

When Not To Use It

If you have established coding standards using a different naming convention (separating words with underscores), turn this rule off.

如果你已经建立了编码标准，使用了不同的命名约定(用下划线分隔单词)，关闭此规则即可。

Version

This rule was introduced in ESLint 0.0.2.

该规则在 ESLint 0.0.2 被引入。

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