noDuplicateCase

诊断类别：lint/suspicious/noDuplicateCase

¥Diagnostic Category: lint/suspicious/noDuplicateCase

JavaScript (and super languages)

自从：v1.0.0

¥Since: v1.0.0

来源：

¥Sources:

与以下相同：no-duplicate-case

¥Same as: no-duplicate-case

禁止重复的案例标签。

¥Disallow duplicate case labels.

如果 switch 语句在 case 子句中有重复的测试表达式，则程序员很可能复制了 case 子句但忘记更改测试表达式。

¥If a switch statement has duplicate test expressions in case clauses, it is likely that a programmer copied a case clause but forgot to change the test expression.

示例

¥Examples

无效

¥Invalid

switch (a) {
    case 1:
        break;
    case 1:
        break;
    default:
        break;
}

code-block.js:4:10 lint/suspicious/noDuplicateCase ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Duplicate case label.
  
    2 │     case 1:
    3 │         break;
  > 4 │     case 1:
      │          ^
    5 │         break;
    6 │     default:
  
  ℹ The first similar label is here:
  
    1 │ switch (a) {
  > 2 │     case 1:
      │          ^
    3 │         break;
    4 │     case 1:

switch (a) {
    case one:
        break;
    case one:
        break;
    default:
        break;
}

code-block.js:4:10 lint/suspicious/noDuplicateCase ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Duplicate case label.
  
    2 │     case one:
    3 │         break;
  > 4 │     case one:
      │          ^^^
    5 │         break;
    6 │     default:
  
  ℹ The first similar label is here:
  
    1 │ switch (a) {
  > 2 │     case one:
      │          ^^^
    3 │         break;
    4 │     case one:

switch (a) {
    case "1":
        break;
    case "1":
        break;
    default:
        break;
}

code-block.js:4:10 lint/suspicious/noDuplicateCase ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Duplicate case label.
  
    2 │     case “1”:
    3 │         break;
  > 4 │     case “1”:
      │          ^^^
    5 │         break;
    6 │     default:
  
  ℹ The first similar label is here:
  
    1 │ switch (a) {
  > 2 │     case “1”:
      │          ^^^
    3 │         break;
    4 │     case “1”:

有效

¥Valid

switch (a) {
    case 1:
        break;
    case 2:
        break;
    default:
        break;
}

switch (a) {
    case one:
        break;
    case two:
        break;
    default:
        break;
}

switch (a) {
    case "1":
        break;
    case "2":
        break;
    default:
        break;
}

noDuplicateCase

示例

无效

有效

相关链接