--- id: 56533eb9ac21ba0edf2244db title: 介紹 else if 語句 challengeType: 1 videoUrl: 'https://scrimba.com/c/caeJ2hm' forumTopicId: 18206 dashedName: introducing-else-if-statements --- # --description-- 如果你有多個條件語句,你可以通過 `else if` 語句把 `if` 語句鏈起來。 ```js if (num > 15) { return "Bigger than 15"; } else if (num < 5) { return "Smaller than 5"; } else { return "Between 5 and 15"; } ``` # --instructions-- 使用 `else if` 實現同樣的效果。 # --hints-- 你應該至少有兩個 `else` 表達式。 ```js assert(code.match(/else/g).length > 1); ``` 你應該至少有兩個 `if` 表達式。 ```js assert(code.match(/if/g).length > 1); ``` 應該關閉每一個 `if else` 代碼塊。 ```js assert( code.match( /if\s*\((.+)\)\s*\{[\s\S]+\}\s*else\s+if\s*\((.+)\)\s*\{[\s\S]+\}\s*else\s*\{[\s\S]+\s*\}/ ) ); ``` `testElseIf(0)` 應該返回字符串 `Smaller than 5` ```js assert(testElseIf(0) === 'Smaller than 5'); ``` `testElseIf(5)` 應該返回字符串 `Between 5 and 10` ```js assert(testElseIf(5) === 'Between 5 and 10'); ``` `testElseIf(7)` 應該返回字符串 `Between 5 and 10` ```js assert(testElseIf(7) === 'Between 5 and 10'); ``` `testElseIf(10)` 應該返回字符串 `Between 5 and 10` ```js assert(testElseIf(10) === 'Between 5 and 10'); ``` `testElseIf(12)` 應該返回字符串 `Greater than 10` ```js assert(testElseIf(12) === 'Greater than 10'); ``` # --seed-- ## --seed-contents-- ```js function testElseIf(val) { if (val > 10) { return "Greater than 10"; } if (val < 5) { return "Smaller than 5"; } return "Between 5 and 10"; } testElseIf(7); ``` # --solutions-- ```js function testElseIf(val) { if(val > 10) { return "Greater than 10"; } else if(val < 5) { return "Smaller than 5"; } else { return "Between 5 and 10"; } } ```