ESLintEnforce spacing before and after semicolons (semi-spacing)
强制分号前后有空格 (semi-spacing)
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。
JavaScript allows you to place unnecessary spaces before or after a semicolon.
JavaScript 允许你在分号前后放置不必要的空格。
Disallowing or enforcing space around a semicolon can improve the readability of your program.
禁止或强制分号周围的空格可以提高你程序的可读性。
var a = "b" ;
var c = "d";var e = "f";
Rule Details
This rule aims to enforce spacing around a semicolon. This rule prevents the use of spaces before a semicolon in expressions.
该该规则旨在强制分号周围的空格。该规则防止在表达式中的分号之前使用空格。
This rule doesn’t check spacing in the following cases:
该规则在以下情况下不会检查空格：
- The spacing after the semicolon if it is the first token in the line.
- 行首分号后面的空格
- The spacing before the semicolon if it is after an opening parenthesis (
(or{), or the spacing after the semicolon if it is before a closing parenthesis ()or}). That spacing is checked byspace-in-parensorblock-spacing. - 开括号 (
(或{) 之后、分号之前的空格，或分号之后、闭括号 ()或}) 之前的空格。这个空格被space-in-parens或block-spacing规则检查。 - The spacing around the semicolon in a for loop with an empty condition (
for(;;)). - 空条件 (
for(;;)) 的 for 循环语句中分号周围的空格。
Options
The rule takes one option, an object, which has two keys before and after having boolean values true or false.
该规则有一个可选项，是个对象，有两个键 before 和 after 对应的值为布尔类型的值 true 或 false。
If before is true, space is enforced before semicolons and if it’s false, space is disallowed before semicolons.
如果设置 before 为 true，分号之前强制有空格，如果设置为 false，分号之前禁止有空格。
If after is true, space is enforced after semicolons and if it’s false, space is disallowed after semicolons.
如果设置 after 为 true.分号之后强制有空格，如果设置为 false，分号之后禁止有空格。
The after option will be only applied if a semicolon is not at the end of line.
after 选项只在分号不是行尾时起作用。
The default is {"before": false, "after": true}.
默认选项为 {"before": false, "after": true}。
"semi-spacing": ["error", {"before": false, "after": true}]
{"before": false, "after": true}
This is the default option. It enforces spacing after semicolons and disallows spacing before semicolons.
这个是默认选项，它强制分号之后有空格，禁止分号之前有空格。
Examples of incorrect code for this rule:
错误 代码示例：
/*eslint semi-spacing: "error"*/
var foo ;
var foo;var bar;
throw new Error("error") ;
while (a) { break ; }
for (i = 0 ; i < 10 ; i++) {}
for (i = 0;i < 10;i++) {}
Examples of correct code for this rule:
正确 代码示例：
/*eslint semi-spacing: "error"*/
var foo;
var foo; var bar;
throw new Error("error");
while (a) { break; }
for (i = 0; i < 10; i++) {}
for (;;) {}
if (true) {;}
;foo();
{"before": true, "after": false}
This option enforces spacing before semicolons and disallows spacing after semicolons.
这个选项强制分号之前有空格，禁止分号之后有空格。
Examples of incorrect code for this rule with the {"before": true, "after": false} option:
选项 {"before": true, "after": false} 的 错误 代码示例：
/*eslint semi-spacing: ["error", { "before": true, "after": false }]*/
var foo;
var foo ; var bar;
throw new Error("error");
while (a) { break; }
for (i = 0;i < 10;i++) {}
for (i = 0; i < 10; i++) {}
Examples of correct code for this rule with the {"before": true, "after": false} option:
选项 {"before": true, "after": false} 的 正确 代码示例：
/*eslint semi-spacing: ["error", { "before": true, "after": false }]*/
var foo ;
var foo ;var bar ;
throw new Error("error") ;
while (a) {break ;}
for (i = 0 ;i < 10 ;i++) {}
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing before or after semicolons.
如果你不关心分号之前或之后的空格的一致性，你可以关闭此规则。
Related Rules
Version
This rule was introduced in ESLint 0.16.0.
该规则在 ESLint 0.16.0 中被引入。