--- id: 587d7b89367417b2b2512b49 title: 使用解構賦值從對象中分配變量 challengeType: 1 forumTopicId: 301215 dashedName: use-destructuring-assignment-to-assign-variables-from-objects --- # --description-- 可以給解構的值賦予一個新的變量名, 通過在賦值的時候將新的變量名放在冒號後面來實現。 還是以上個例子的對象來舉例: ```js const user = { name: 'John Doe', age: 34 }; ``` 這是指定新的變量名的例子: ```js const { name: userName, age: userAge } = user; ``` 你可以這麼理解這段代碼:獲取 `user.name` 的值,將它賦給一個新的變量 `userName`,等等。 `userName` 的值將是字符串 `John Doe`,`userAge` 的值將是數字 `34`。 # --instructions-- 使用解構賦值語句替換兩個賦值語句。 將 `HIGH_TEMPERATURES` 的 `today` 和 `tomorrow` 的值賦值給 `highToday` 和 `highTomorrow`。 # --hints-- 應該移除 ES5 賦值語句。 ```js assert( !code.match(/highToday = HIGH_TEMPERATURES\.today/g) && !code.match(/highTomorrow = HIGH_TEMPERATURES\.tomorrow/g) ); ``` 應該使用解構賦值語句創建 `highToday` 變量。 ```js assert( code.match( /(var|const|let)\s*{\s*(today\s*:\s*highToday[^}]*|[^,]*,\s*today\s*:\s*highToday\s*)}\s*=\s*HIGH_TEMPERATURES(;|\s+|\/\/)/g ) ); ``` 應該使用解構賦值語句創建 `highTomorrow` 變量。 ```js assert( code.match( /(var|const|let)\s*{\s*(tomorrow\s*:\s*highTomorrow[^}]*|[^,]*,\s*tomorrow\s*:\s*highTomorrow\s*)}\s*=\s*HIGH_TEMPERATURES(;|\s+|\/\/)/g ) ); ``` `highToday` 應該等於 `77`,`highTomorrow` 應該等於 `80`。 ```js assert(highToday === 77 && highTomorrow === 80); ``` # --seed-- ## --seed-contents-- ```js const HIGH_TEMPERATURES = { yesterday: 75, today: 77, tomorrow: 80 }; // Only change code below this line const highToday = HIGH_TEMPERATURES.today; const highTomorrow = HIGH_TEMPERATURES.tomorrow; // Only change code above this line ``` # --solutions-- ```js const HIGH_TEMPERATURES = { yesterday: 75, today: 77, tomorrow: 80 }; const { today: highToday, tomorrow: highTomorrow } = HIGH_TEMPERATURES; ```