Disallow Unnecessary Labels (no-extra-label)

禁用不必要的标签 (no-extra-label)

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。

If a loop contains no nested loops or switches, labeling the loop is unnecessary.

如果一个循环中不包含嵌套循环或 switch 语句，对这样的循环使用标签是不必要的。

A: while (a) {
    break A;
}

You can achieve the same result by removing the label and using break or continue without a label. Probably those labels would confuse developers because they expect labels to jump to further.

你可以通过移除标签，只使用 break 或 continue实现同样的结果。这些标签可能会使开发者感到困惑，因为他们可能希望使用标签跳转到更远的地方。

Rule Details

This rule is aimed at eliminating unnecessary labels.

该规则旨在消除不必要的标签。

Examples of incorrect code for this rule:

错误 代码示例：

/*eslint no-extra-label: "error"*/

A: while (a) {
    break A;
}

B: for (let i = 0; i < 10; ++i) {
    break B;
}

C: switch (a) {
    case 0:
        break C;
}

Examples of correct code for this rule:

正确 代码示例：

/*eslint no-extra-label: "error"*/

while (a) {
    break;
}

for (let i = 0; i < 10; ++i) {
    break;
}

switch (a) {
    case 0:
        break;
}

A: {
    break A;
}

B: while (a) {
    while (b) {
        break B;
    }
}

C: switch (a) {
    case 0:
        while (b) {
            break C;
        }
        break;
}

When Not To Use It

If you don’t want to be notified about usage of labels, then it’s safe to disable this rule.

如果你不想收到有关标签的使用情况的通知，关闭此规则即可。

Version

This rule was introduced in ESLint 2.0.0-rc.0.

该规则在 ESLint 2.0.0-rc.0 中被引入。

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