--- tags: JS 直播班 - 2022 秋季班 --- # 🏅 Day 25 - forEach [`forEach()`](https://developer.mozilla.org/zh-TW/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach) 是屬於 **「陣列」** 的方法，會將陣列內的每個元素一一傳入，並依序執行函式。 `forEach()` 內的函式常見會帶有三個參數，以下為用法示例： ```javascript= let data = ["a", "b", "c"]; // 參數 item 代表陣列中目前正在被處理的那個元素 // 參數 index 代表陣列中目前正在被處理的那個元素的索引值 // 參數 array 代表被處理的陣列本身，在此為 data data.forEach(function(item, index, array){ console.log(item, index, array); }) ``` 執行結果: ![](https://i.imgur.com/NuRNgjX.png) **這邊需要特別提醒，在 `forEach()` 函式內用 return 無法停止函式進行下一個 item。除非程式碼有誤，否則並沒有中止 `forEach()` 的辦法** ```javascript= let data = ["a", "b", "c"]; data.forEach(function(item, index, array){ console.log(item, index, array); // 程式碼會忽略這個 return return }) ``` 問題 --- 請根據以下要求撰寫程式碼: > 1. 如果 numberAll 陣列內的值大於或等於 30，則用 `push()` 方法將其加入 NumberAbove30 陣列中。 > 2. 如果 numberAll 陣列內的值小於 30，則用 `push()` 方法將其加入 numberUnder30 陣列中。 ```javascript= let numberAll = [25, 30, 15, 50, 17, 40]; let numberAbove30 = []; let numberUnder30 = []; numberAll.forEach(function(/* 填入參數 */){ if (/* 填入判斷式 */) { /* 程式碼撰寫處 */ } else { /* 程式碼撰寫處 */ } }); console.log(numberAbove30); console.log(numberUnder30); ``` ## 回報流程 將答案寫在 CodePen 並複製 CodePen 連結貼至底下回報就算完成了喔! 解答位置請參考下圖（需打開程式碼的部分觀看） ![](https://i.imgur.com/vftL5i0.png) <!-- 解答： let numberAll = [25, 30, 15, 50, 17, 40]; let numberAbove30 = []; let numberUnder30 = []; numberAll.forEach(function(item) { if (item >= 30) { numberAbove30.push(item); } else { numberUnder30.push(item); } }); console.log(numberAbove30); console.log(numberUnder30); --> 回報區 --- | Discord | CodePen / 答案 | |:---------------:|:----------------------------------------------------------------------------:| | suihsilan#9485 | [Codepen](https://codepen.io/suihsilan/pen/zYaBKaB?editors=0010) | | yumy#1940 | [CodePen](https://codepen.io/yumy_yang/pen/XWYKjYd) | | shinyhung#3825 | [Codepen](https://codepen.io/sean_1215/pen/YzvWGOY?editors=1111) | | YC#2522 | [CodePen](https://codepen.io/YCLu/pen/jOKbxEO) | | xherobruce#6825 | [CodePen](https://codepen.io/winwinbruce/pen/JjZKRmN) | | 予予#9627 | [CodePen](https://codepen.io/kiqzcraa/pen/xxzOEmq?editors=0011) | | 無名#6427 | [CodePen](https://codepen.io/Nomoney/pen/KKeMgJP?editors=0011) | | hsiung阿熊#4079 | [Codepen](https://codepen.io/hsiungchi/pen/zYaBKbo) | | AuroraC#6539 | [codepen](https://codepen.io/AuroraC/pen/vYrKXMj?editors=1012) | | yoshidc#0455 | [CodePen](https://codepen.io/yoshiyyc/pen/qBKNaGP) | | RJRS#9430 | [CodePen](https://codepen.io/RJRS/pen/JjZKRZW) | | Data#9297 | [CodePen](https://codepen.io/kirakira72/pen/vYrKXVR) | | 薯餅#3581 | [CodePen](https://codepen.io/ColdingPoTaTo/pen/vYrKyBa) | | 圈圈#4060 | [codepeb](https://codepen.io/wjejfczn-the-bold/pen/KKeMNwp?editors=1111) | | Hazel.#6020 | [codepen](https://codepen.io/Hazelhsieh/pen/zYaBoxZ?editors=0011) | | Kimi #9564 | [Codepen](https://codepen.io/kimihu91/pen/WNyQaeo) | | 威0#6919 | [codepen](https://codepen.io/n0918679182/pen/PoazbJM?editors=0012) | | Rr#2215 | [Codepen](https://codepen.io/rufangcheng/pen/yLEJVvg) | | 心幻羽#0056 | [codepen](https://codepen.io/linglingsyu/pen/vYrKydP?editors=1111) | | azami#5986 | [Codepen](https://codepen.io/azami/pen/xxzORYj) | | banazita#5143 | [CodePen](https://codepen.io/banazita/pen/vYrKypb?editors=0011) | | 末次#0236 | [CodePen](https://codepen.io/yunjulee/pen/qBKNqYy) | | LHchien33#6232 | [CodePen](https://codepen.io/lin_chien/pen/RwJRoYm?editors=0011) | | 母湯#7211 | [CodePen](https://codepen.io/tommyshih77/pen/poKbNxe?editors=0011) | | CofCat#9226 | [CodePen](https://codepen.io/cofcat456/pen/ExRyNrR?editors=1111) | | VT#0895 | [Codepen](https://codepen.io/vt197/pen/GRGqNbg) | | 大衛#4869 | [Codepen](https://codepen.io/exnsrpjc/pen/QWxEGep?editors=1011) | | CloThEs#7837 | [Codepen](https://codepen.io/CloThEsZ/pen/poKbRoW) | | 威爾#1694 | [CodePen](https://codepen.io/WILL_Wu/pen/bGKegNB) | | JustinLiu#9699 | [CodePen](https://codepen.io/justin0227/pen/qBKNREg?editors=0011) | | kuku#3118 | [Cpdepen](https://codepen.io/mengting-ku/pen/YzvWNPm) | | masterYan#2480 | [CodePen](https://codepen.io/htzwgoqt-the-looper/pen/QWxEdjg?editors=1011) | | Peng#9811 | [CodePen](https://codepen.io/peng-027/pen/zYaBNrJ) | | mandylai#4055 | [CodePen](https://codepen.io/mandy-lai-2/pen/OJEXWXR?editors=1111) | | amy芳#1385 | [CodePen](https://codepen.io/amy-chieng/pen/jOKryNm) | | Jenny真#7532 | [CodePen](https://codepen.io/wei-chen-wu/pen/ExRyZWG?editors=0010) | | Arista#5802 | [CodePen](https://codepen.io/arista-hsieh/pen/ExRyZmr) | | Eileen#6454 | [CodePen](https://codepen.io/Eileen-io/pen/JjZKEWV) | | RyanTsai#8906 | [CodePen](https://codepen.io/linlaose/pen/PoazWOW) | | christina#6185 | [Codepen](https://codepen.io/chrisc0210/pen/wvXWgpe) | | 肉桂卷#0625 | [CodePen](https://codepen.io/ginnlee/pen/MWXeJvX?editors=0011) | | yawun#0042 | [CodePen](https://codepen.io/monicalin/pen/mdKERMP) | | Winnie#1306 | [Codepen](https://codepen.io/WinnieWuWinnie/pen/qBKNRJB?editors=0012) | | Cookie SSS#6991 | [Codepen](https://codepen.io/sqhjikpa-the-selector/pen/qBKNRQE?editors=1012) | | Benson#6763 | [Codepen](https://codepen.io/kumashow/pen/OJEXWrj) | | jimmyFang#9575 | [Codepen](https://codepen.io/pohxiqqo/pen/XWYKpQw?editors=0010) | | hungya#0773 | [Codepen](https://codepen.io/hungya777/pen/mdKERaR?editors=0011) | | Hilda#7085 | [Codepen](https://codepen.io/vwquikad-the-vuer/pen/JjZKWRX) | | PayRoom | [CodePen](https://codepen.io/water38198/pen/yLEJMar) | | jackson204#6363 | [CodePen](https://codepen.io/jackson204/pen/gOKMmLo) | | Loran#1105 | [CodePen](https://codepen.io/loranlin/pen/NWzrpaE?editors=1011) | | yaru#6308 | [CodePen](https://codepen.io/lszaietc/pen/ExRyWbK?editors=1011) | |法希娜#3206|[codepen](https://codepen.io/yiiserpf-the-encoder/pen/zYaBZRr?editors=1011) | |KC_8685#9343|[Codepen](https://codepen.io/cathy7411/pen/qBKNrPq)| |hannahTW#2224|[Codepen](https://codepen.io/hangineer/pen/jOKrBvj?editors=1011)| |Ruby Chen#7452|[Codepen](https://codepen.io/ruby92429/pen/rNKLyQe?editors=1111)| |Vera#5592|[CodePen](https://codepen.io/skvera/pen/jOKrBdg)| |魚子醬#5220|[CodePen](https://codepen.io/haihsuan/pen/zYaBZbo)| |beta lin#1445|[CodePen](https://codepen.io/linbeta/pen/JjZKNjr)| |kenki100#0068|[Codepen](https://codepen.io/ken100/pen/poKbPJj)| |出事了阿伯#9923|[Codepen](https://codepen.io/BradpittLai/pen/XWYKRKR?editors=1011)| |WEI_RIO#9342|[Codepen](https://codepen.io/wei_wu/pen/MWXemee?editors=0011)| |YI#0863|[Codepen](https://codepen.io/YI0305/pen/RwJRgbb?editors=0012)| |竹輪#3335|[Codepen](https://codepen.io/chikuwa0120/pen/ExRyXae)| |Potatolee#7749|[Codepen](https://codepen.io/potatoleee/pen/VwdjWvo?editors=1011)| | 小白#2406 | [CodePen](https://codepen.io/gracewhite/pen/YzvWQGz) | |粉蒸肉#6214|[Codepen](https://codepen.io/wrightyu/pen/oNyLwWK?editors=1111)| |雷雷#7844|[Codepen](https://codepen.io/lei-yi-jie/pen/NWzrggg?editors=0011)| |軟綿綿 (๑•ᴗ•๑) ♡#3627|[CodePen](https://codepen.io/Connie-Chien/pen/VwdjWrY?editors=0011)| |楓之聲#6945|[Codepen](https://codepen.io/sshane258/pen/KKeMqJB)| |Mylène#2481|[Codepen](https://codepen.io/hamajibashi/pen/eYKzRaX)| |#Yiru0236|[Codepen](https://codepen.io/yiru94/pen/wvXWeXq?editors=0011)| |Amberhh#2465| [Codepen](https://codepen.io/Amberhh/pen/BaVKGXr?editors=0011) | | m_m#5493 | [CodePen](https://codepen.io/minnn7716/pen/jOKrwjp) | |jacky010080#0880|[CodePen](https://codepen.io/Yen-Jung-Chen/pen/QWxEMyZ?editors=0012)| |萱仔#0781|[Codepen](https://codepen.io/ting-hsuan/pen/abKZLjY?editors=0010)| |Hironaka#7367|[Codepen](https://codepen.io/Hironaka0815/pen/GRGqMLK?editors=0010)| |勁辣雞腿寶#5817|[Codepen](https://codepen.io/orz311013/pen/MWXeOpG?editors=1011) |Lucie#3831|[Codepen](https://codepen.io/bisespei/pen/abKZqzW)| |yen#5757|[Codepen](https://codepen.io/wjejfczn-the-bold/pen/KKeMNwp?editors=1111)| |JackC#0411|[Codepen](https://codepen.io/key0329/pen/mdKEXBo)| |黑松胖#4836|[Codepen](https://codepen.io/yi-chien-hsieh/pen/vYrKRNB?editors=0012)| |Sentiments#4883|[codepen](https://codepen.io/Sentiments/pen/oNyLqLR?editors=1011) |柔柔#1716|[Codepen](https://codepen.io/rouchen/pen/yLEJjJw?editors=0011)| |王懷英#7271|[CodePen](https://codepen.io/huaiying/pen/dyKXeZW) |mou#2215|[CodePen](https://codepen.io/shihchiehlan/pen/OJEXZKr?editors=0111)| | 黃士桓#7654 | [codePen](https://codepen.io/shr-huan-huang/pen/YzvWvMM) | |Judy Wei#6103|[CodePen](https://codepen.io/Judy0718/pen/NWzrBgj)| |RayChen#6088|[CodePen](https://codepen.io/raychen1996/pen/mdKEGoL)| |shio#1414|[CodePen](https://codepen.io/shioyen/pen/PoazgOR?editors=1111)| |Ryan Chiang#6649|[Codepen](https://codepen.io/ryanchiang/pen/VwdjOzB?editors=0012)| |Cynthia1111#1822|[Codepen](https://codepen.io/Cynthia1111/pen/GRGqaaV)| |yoyo#1003|[Codepen](https://codepen.io/crpbugqy-the-typescripter/pen/JjZKQGe)| | cbs#9007 |[Codepen](https://codepen.io/wasdjk/pen/ExRgYNm)| |Shuo#1596 |[Codepen](https://codepen.io/chiangchungshuo/pen/WNyoRxr)| |IreneY#0086|[codepen](https://codepen.io/HalfPlannedJourney/pen/YzvpYmV)| |Yuna Huang#2692|[codepen](https://codepen.io/Yuna1002/pen/poKNppO?editors=0011)| |charlottelee849#0366|[codepen](https://codepen.io/charlotte-lee/pen/KKeNQYd?editors=0012)| |L0F0#8733|[codepen](https://codepen.io/l0f0/pen/ZERBoJm?editors=0011)| |Tami#6742|[CodePen](https://codepen.io/wqsdqbjn-the-vuer/pen/oNyYyZw)| |三隻小貓#1905|[CodePen](https://codepen.io/bagelover/pen/oNyYMLM?editors=0011)| |Rena#6249|[Codepen](https://codepen.io/aureate0116/pen/rNKWZdR?editors=1111)| |安o#2448|[codepen](https://codepen.io/JzhenAn/pen/NWzbeaw?editors=1111)| |Lou#0085|[codepen](https://codepen.io/Lusie_H/pen/VwdmOab?editors=0011)| |kancheng#3915|[CodePen](https://codepen.io/kancheng/pen/rNKjBRM?editors=0110)| |芮綺#5224|[CodePen](https://codepen.io/zhan70/pen/eYKgdEP?editors=0011)| |Ron Liang#7277|[CodePen](https://codepen.io/ron-go/pen/abKpmYr)| |Wei#2330|[Codepen](https://codepen.io/ixfjxrbo-the-typescripter/pen/OJEWpMX)| |Velma#1693|[Codepen](https://codepen.io/Ze1225/pen/PoaWpRp)| |Yishan#4902|[Codepen](https://codepen.io/gdjrehhw-the-animator/pen/gOKgxpa?editors=0011)| |健育#5748|[Codepen](https://codepen.io/c1317156/pen/zYaNRWr?editors=1111)| |Paul#7426|[CodePen](https://codepen.io/paul-1997/pen/GRGWjGZ?editors=0011)| |Cliff#4606|[Codepen](https://codepen.io/Cliff_hex/pen/poKeQrJ?editors=1011)| |FiReBrO#0557|[Codepen](https://codepen.io/firebro42/pen/eYKvXvZ)| |sophiee#7015|[Codepen](https://codepen.io/sophiee2727/pen/PoajpOM?editors=1111)| |君Jyun#0147|[codepen](https://codepen.io/Okaybeok/pen/vYrJExz?editors=1011)| |艾芮絲#6060|[codepen](https://codepen.io/wangyingju/pen/poKWZeK)| |狸貓#5863|[codepen](https://codepen.io/tanuki320/pen/eYKGavR?editors=0010)| |ling chang#1024|[codepen](https://codepen.io/ling-chang/pen/WNydeJQ)| |Baozi#2042|[codepen](https://codepen.io/lillianyu/pen/qBKpJdm)| |pss940909#8650|[codepen](https://codepen.io/pss940909/pen/poKajeP?editors=1011)| |阿風#6890|[codepen](https://codepen.io/Afonguwu/pen/mdKXqrY)| |Chloe#5422|[Codepen](https://codepen.io/Ironchloe/pen/GRGQONb?editors=1011)| |入門小菜G#0191|[Codepen](https://codepen.io/DennisLiu123123/pen/oNyqQxE)| |阿蘇#8531|[Codepen](https://codepen.io/susu3131/pen/abKKrrz?editors=0011)| |郭芙蘭#6374|[Codepen](https://codepen.io/flora_Kuo/pen/bGKxMbO?editors=1111)| |Judy #7874|[CodePen](https://codepen.io/hsiaohan/pen/OJErMgQ?editors=1011)| |Ringo #7583|[CodePen](https://codepen.io/ringolai1988/pen/WNyLpPP?editors=0010)| |Mia小福#4473|[CodePen](https://codepen.io/a0950271/pen/MWXLEBK?editors=1111)| |samger#0808|[CodePen](https://codepen.io/lee-wei-hong/pen/QWxodzd?editors=1111)| |教練#6451|[CodePen](https://codepen.io/monkeybear721/pen/vYrwMGv?editors=1111)| |Azi Hsieh#2861|[CodePen](https://codepen.io/AziHsieh/pen/PoaMrjJ)| |J_u_d_y#5993|[Codepen](https://codepen.io/J_u_d_y/pen/MWBPeaW?editors=1111)|