# 🏅 Day 26 - addEventListener 事件監聽 ### addEventListener 語法 `.addEventListener()` 前面會放欲選取的元素, `addEventListener()` 內通常會代入兩個參數,第一個參數為事件類型,第二個參數觸發事件後要執行的動作(函式) 範例: HTML ```htmlembedded= <p class="domElement">123</p> ``` JS ```javascript= const domElement = document.querySelector(".domElement"); domElement.addEventListener("click", function(e) { // 觸發時欲執行的程式 console.log(e); // 以此範例來說,點擊 p.domElement 元素時就會印出參數 e(參數名稱可以自訂,這邊定為 e 有 event 的意思) // 此參數為一個事件物件,包含了與此事件有關的屬性 // 可以嘗試觀看 e 的內容 // 像是: // target 屬性為觸發事件時的元素 // type 屬性為觸發事件的類型 }); ``` > 在指定元素(domElement)監聽特定事件(此範例為 click 事件,需使用引號),當該事件觸發時會執行後方函式,函式有一個參數為事件物件 ### 常用事件介紹 1. click:滑鼠點擊元素時會觸發 2. change:當表單內容改變時會觸發 3. scroll:滾動時觸發 > 更多可以再觀看 [文件](https://developer.mozilla.org/zh-TW/docs/Web/Events) 補充: - [MDN 文件](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener) - https://israynotarray.com/javascript/20190919/1187569768/ 問題 --- 監聽下方元素(.plusOne),當點擊「+1」按鈕時,可以讓 sum 的值 +1,並使用 console.log 印出 sum。 HTML ```htmlembedded= <button type="button" class="plusOne">+1</button> ``` JS ```javascript= let sum = 0; /* 程式碼撰寫 */ ... ``` ## 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 sum = 0; /* 程式碼撰寫 */ const plusOne = document.querySelector(".plusOne"); plusOne.addEventListener("click", function() { sum++; console.log(sum); }) --> 回報區 --- | # | Discord | CodePen / 答案 | | --- | ----- | ----- | | 01 | voke | [CodePen](https://codepen.io/FiSi-the-lessful/pen/oNKoBYN) | | 02 | 泊岸 | [CodePen](https://codepen.io/qoq77416416/pen/ExqpNXz?editors=1011) | | 03 | 毛巾 | [CodePen](https://codepen.io/bqdcjboa-the-solid/pen/YzmjpLG) | | 04 | david1819 | [CodePen](https://codepen.io/David-Lin-the-vuer/pen/GRVBNOW) | | 05 | 睿睿 |[CodePen](https://codepen.io/uwmrsusb-the-solid/pen/abejBXz?editors=1011)| | 06 | 嚼勁先生 |[CodePen](https://codepen.io/James520284/pen/bGXjBQM)| | 07 | tim |[CodePen](https://codepen.io/jskrtivy-the-animator/pen/zYgLNVz?editors=1011)| | 08 |Tatsu| [CodePen](https://codepen.io/chindesu0207/pen/poMZezy) | | 09 |mercury2508.| [CodePen](https://codepen.io/Mercury2508/pen/poMZeBd) | | 10 | Dolce_墨 | [CodePen](https://codepen.io/DolceTseng1026/pen/abejJXR) | | 11 | Ruby | [CodePen](https://codepen.io/xivgaijl-the-selector/pen/QWeBgwz) | | 12 | yuyuhunter_0509 | [CodePen](https://codepen.io/KRcube/pen/mdNjwJq?editors=1011) | | 13 |Hedwig| [CodePen](https://codepen.io/adirehfz-the-encoder/pen/GRVBvra?editors=1011) | | 14 | 610 | [CodePen](https://codepen.io/YI-LING-LIU/pen/rNXrGMQ?editors=1011) | | 15 | kun._c8_shake_it | [CodePen](https://codepen.io/barry91205/pen/dyxjZeZ?editors=1111) | | 16 | Kaya | [CodePen](https://codepen.io/kayaribi/pen/MWNBreJ) | | 17 | Ariel | [CodePen](https://codepen.io/ariel0510/pen/NWQBXXN?editors=1011) | | 18 | jimmy.0706 | [CodePen](https://codepen.io/JimmyMao/pen/xxvJpMQ?editors=1011) | | 19 | brucelee0629 | [CodePen](https://codepen.io/xxhdklwi-the-decoder/pen/XWvBVyq?editors=1011) | | 20 |yuling | [CodePen](https://codepen.io/yu-ling-peng/pen/NWQByoM?editors=1011) | | 21 | Mos | [CodePen](https://codepen.io/mos25399/pen/abejGvV?editors=1111) | | 22 | Rogan | [CodePen](https://codepen.io/RoganHsu/pen/yLmqjJa?editors=1111) | | 23 | .tsz_ying | [CodePen](https://codepen.io/bekgnohe-the-selector/pen/mdNjKEV?editors=1011) | | 24 | yuyeh_1212 | [CodePen](https://codepen.io/yuyeh1212/pen/ExqpREB) | | 25 | GTR150 | [CodePen](https://codepen.io/Wer-Qwe/pen/eYqjKXa?editors=1111) | | 26 | JIA | [CodePen](https://codepen.io/nzaicwlw-the-styleful/pen/bGXjmao?editors=1011) | | 27 | Celine | [CodePen](https://codepen.io/szuning/pen/abejxWE?editors=0011) | | 28 | Sonia | [CodePen](https://codepen.io/YUJOU/pen/bGXjXMV?editors=1011) | | 29 | charlottelee | [CodePen](https://codepen.io/char849/pen/OJKwKwP) | | 30 | Jainee | [CodePen](https://codepen.io/Jainee0110/pen/GRVXRKv) | | 31 | ab567ab5 | [CodePen](https://codepen.io/WanTzu-Chiang/pen/jOgvPgv?editors=1011) | | 32 | Mike | [CodePen](https://codepen.io/mike2049/pen/jOgvqZZ?editors=1011) | | 33 | 是在哈囉 | [CodePen](https://codepen.io/miyxdhem-the-solid/pen/ExqeWpQ) | | 34| 邵 |[CodePen](https://codepen.io/ukscrlno-the-typescripter/pen/poMOPLV?editors=1011)| | 35 | chris | [CodePen](https://codepen.io/chris-chen-the-selector/pen/abeawMp?editors=1111) | | 36 | ycl325.etheddie | [CodePen](https://codepen.io/wdvikfuz-the-selector/pen/zYgJdjP) | | 37 | Lotte | [CodePen](https://codepen.io/hmkdoxuj-the-decoder/pen/MWNqxjL?editors=1011) | | 39 | 陳小廷 | [CodePen](https://codepen.io/ting1124/pen/GRVYQWR) | | 40 | alec1203 | [CodePen](https://codepen.io/soloayaya/pen/MWNzOjB?editors=1012) | | 41 | joylu0902 | [CodePen](https://codepen.io/joylu0902/pen/ZEgmWyJ) | | 42 | jerry_66983 | [CodePen](https://codepen.io/Barry-C/pen/wvVQjMx?editors=1011) | | 43 | Joannehu | [CodePen](https://codepen.io/nelbabkv-the-flexboxer/pen/dyxQeXW?editors=1011) | | 44 | Emma | [CodePen](https://codepen.io/Emma0919/pen/wvVQLLy) | | 45 | 野鴿 | [CodePen](https://codepen.io/HoshinoSyouta/pen/vYovydb?editors=1011) | | 46 | Glen_69515 | [CodePen](https://codepen.io/glenyaochih/pen/GRVPMNP?editors=1111)| |47|Hailey|[CodePen](https://codepen.io/sxbokfja-the-flexboxer/pen/KKObZrj?editors=1111)| |48|JRz|[CodePen](https://codepen.io/JRZHENG/pen/yLmwQaa?editors=1111)| |49|KOMATSU PEI|[CodePen](https://codepen.io/Komatsu2021/pen/mdNgYjp?editors=1011)| | 50 | Jack |[CodePen](https://codepen.io/kxbhixte-the-sasster/pen/gOVJbRa?editors=1011)| |51|Amy(咂摳)| [CodePen](https://codepen.io/nnxucgmc-the-builder/pen/mdNYJww?editors=0011) | | 52 | Nocab |[CodePen](https://codepen.io/PeihanWang/pen/NWQVYeP?editors=1011)| | 52 | 蘑菇星星 |[CodePen](https://codepen.io/brrrieon-the-vuer/pen/KwPPNLo?editors=1112)| | 53 | Ana | [Codepen](https://codepen.io/Ana-Wu/pen/VYZZbQo) | | 54 | Seris | [Codepen](https://codepen.io/Dale-Chien/pen/dPbbZgv) | | 55 | Chuang | [Codepen](https://codepen.io/uidoytjq-the-solid/pen/ZYzqQRj?editors=1011) <!-- 可複製下方格式 | | | [CodePen]() | -->