题解 | #全选#
全选
https://www.nowcoder.com/practice/84b89f326e3c4e96bacb63296e84623a
本地能过 但是可能不是题目所需要的,所以在线编辑器通过不了
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> </head> <style> ul { list-style: none; } </style> <body> <ul> <li>全选<input type='checkbox' id='all' onchange="handleAllChange(this.checked)"></li> <li>Java<input type='checkbox' class='item' onchange="handleItemChange()"></li> <li>javaScript<input type='checkbox' class='item' onchange="handleItemChange()"></li> <li>C++<input type='checkbox' class='item' onchange="handleItemChange()"></li> <li>python<input type='checkbox' class='item' onchange="handleItemChange()"></li> <li>.net<input type='checkbox' class='item' onchange="handleItemChange()"></li> </ul> <script> // 补全代码 let itemList = Array.from(document.getElementsByClassName('item')); let all = document.getElementById('all'); function handleItemChange() { for (let index = 0; index < itemList.length; index++) { if (!itemList[index].checked) { all.checked = false; return; } all.checked = true; } } function handleAllChange(val) { if (val) { for (let index = 0; index < itemList.length; index++) { itemList[index].checked = true; } } else { for (let index = 0; index < itemList.length; index++) { itemList[index].checked = false; } } } </script> </body> </html>