no-extra-label

Disallow unnecessary labels

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

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.

Rule Details

This rule is aimed at eliminating unnecessary labels.

Examples of incorrect code for this rule:

/*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:

/*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.

Related Rules

• no-labels
• no-label-var
• no-unused-labels

Version

This rule was introduced in ESLint v2.0.0-rc.0.

Resources

• Rule source
• Tests source