--- id: 56533eb9ac21ba0edf2244df title: 在 Switch 语句添加多个相同选项 challengeType: 1 videoUrl: 'https://scrimba.com/c/cdBKWCV' forumTopicId: 18242 dashedName: multiple-identical-options-in-switch-statements --- # --description-- 如果你忘了给 `switch` 的每一条 `case` 添加 `break`,那么后续的 `case` 会一直执行,直到遇见 `break` 为止。 如果你想为 `switch` 中的多个不同的输入设置相同的结果,可以这样写: ```js var result = ""; switch(val) { case 1: case 2: case 3: result = "1, 2, or 3"; break; case 4: result = "4 alone"; } ``` 这样,1、2、3 都会有相同的结果。 # --instructions-- 请写一个 switch 语句,按如下条件设置 `answer` : `1-3` - `Low` `4-6` - `Mid` `7-9` - `High` **提示:** 你的 `case` 应写全范围中的每一个数字。 # --hints-- `sequentialSizes(1)` 应该返回字符串 `Low` ```js assert(sequentialSizes(1) === 'Low'); ``` `sequentialSizes(2)` 应该返回字符串 `Low` ```js assert(sequentialSizes(2) === 'Low'); ``` `sequentialSizes(3)` 应该返回字符串 `Low` ```js assert(sequentialSizes(3) === 'Low'); ``` `sequentialSizes(4)` 应该返回字符串 `Mid` ```js assert(sequentialSizes(4) === 'Mid'); ``` `sequentialSizes(5)` 应该返回字符串 `Mid` ```js assert(sequentialSizes(5) === 'Mid'); ``` `sequentialSizes(6)` 应该返回字符串 `Mid` ```js assert(sequentialSizes(6) === 'Mid'); ``` `sequentialSizes(7)` 应该返回字符串 `High` ```js assert(sequentialSizes(7) === 'High'); ``` `sequentialSizes(8)` 应该返回字符串 `High` ```js assert(sequentialSizes(8) === 'High'); ``` `sequentialSizes(9)` 应该返回字符串 `High` ```js assert(sequentialSizes(9) === 'High'); ``` 你不应使用 `if` 或 `else` 语句。 ```js assert(!/else/g.test(code) || !/if/g.test(code)); ``` 你应该编写 9 个`case`语句。 ```js assert(code.match(/case/g).length === 9); ``` # --seed-- ## --seed-contents-- ```js function sequentialSizes(val) { var answer = ""; // Only change code below this line // Only change code above this line return answer; } sequentialSizes(1); ``` # --solutions-- ```js function sequentialSizes(val) { var answer = ""; switch(val) { case 1: case 2: case 3: answer = "Low"; break; case 4: case 5: case 6: answer = "Mid"; break; case 7: case 8: case 9: answer = "High"; } return answer; } ```