eslint/docs/src/rules/no-extra-label.md

   1 ---
   2 title: no-extra-label
   3 layout: doc
   4 rule_type: suggestion
   5 related_rules:
   6 - no-labels
   7 - no-label-var
   8 - no-unused-labels
   9 ---
  10
  11
  12
  13 If a loop contains no nested loops or switches, labeling the loop is unnecessary.
  14
  15 ```js
  16 A: while (a) {
  17     break A;
  18 }
  19 ```
  20
  21 You can achieve the same result by removing the label and using `break` or `continue` without a label.
  22 Probably those labels would confuse developers because they expect labels to jump to further.
  23
  24 ## Rule Details
  25
  26 This rule is aimed at eliminating unnecessary labels.
  27
  28 Examples of **incorrect** code for this rule:
  29
  30 ::: incorrect
  31
  32 ```js
  33 /*eslint no-extra-label: "error"*/
  34
  35 A: while (a) {
  36     break A;
  37 }
  38
  39 B: for (let i = 0; i < 10; ++i) {
  40     break B;
  41 }
  42
  43 C: switch (a) {
  44     case 0:
  45         break C;
  46 }
  47 ```
  48
  49 :::
  50
  51 Examples of **correct** code for this rule:
  52
  53 ::: correct
  54
  55 ```js
  56 /*eslint no-extra-label: "error"*/
  57
  58 while (a) {
  59     break;
  60 }
  61
  62 for (let i = 0; i < 10; ++i) {
  63     break;
  64 }
  65
  66 switch (a) {
  67     case 0:
  68         break;
  69 }
  70
  71 A: {
  72     break A;
  73 }
  74
  75 B: while (a) {
  76     while (b) {
  77         break B;
  78     }
  79 }
  80
  81 C: switch (a) {
  82     case 0:
  83         while (b) {
  84             break C;
  85         }
  86         break;
  87 }
  88 ```
  89
  90 :::
  91
  92 ## When Not To Use It
  93
  94 If you don't want to be notified about usage of labels, then it's safe to disable this rule.