<input id="isComplexWeld" name="isComplexWeld" style="height:20px " type="checkbox"/>

根据提供的引用内容，代码片段中的<input id="isComplexWeld" name="isComplexWeld" style="height:20px " type="checkbox"/>是一个复选框。这个复选框的样式设置和行为由提供的CSS和JavaScript代码控制。在CSS代码中，.checkbox-item类设置了复选框项的样式，.checkbox-item label:before伪类设置了一个新的复选框，通过点击初始复选框与新复选框进行关联。在JavaScript代码中，通过全选、反选和单个选择的事件处理函数，实现了复选框的选择与取消选择的功能。<span class="em">1</span><span class="em">2</span><span class="em">3</span>
#### 引用[.reference_title]
- *1* *2* [input type=checkbox样式设置](https://blog.csdn.net/glgom/article/details/87707664)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v93^chatsearchT3_2"}}] [.reference_item style="max-width: 50%"]
- *3* [input[type='checkbox']全选反选](https://blog.csdn.net/weixin_42220533/article/details/86525988)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v93^chatsearchT3_2"}}] [.reference_item style="max-width: 50%"]
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