首页 > 文章 > 前端

输入框占位提示设置方法全解析

时间：2026-05-31 22:43:02 439浏览收藏

本文深入解析了HTML中placeholder属性的正确用法与常见误区，涵盖原生HTML书写规范、React动态设置时的坑点（如null/undefined处理）、CSS跨浏览器样式兼容性难题，以及关键的可访问性限制——明确指出placeholder仅适用于轻量格式引导，绝不能替代label、承载敏感信息或承担表单逻辑，并依据WCAG 2.1标准推荐更健壮的替代方案，帮助开发者写出既美观又合规、用户体验与无障碍兼顾的输入框提示。

怎样设置输入框的占位提示_PLACEHOLDER引导内容填写

HTML 中 `placeholder` 属性怎么写才有效

直接在或 </code> 标签里加 <code>placeholder</code> 属性就行，浏览器原生支持，不用 JS 就能显示浅灰色提示文字。</p> <p>常见错误是把它当成默认值或初始值——<code>placeholder</code> 不会提交、不会触发 <code>change</code> 事件、用户一输入就消失，也不能用 <code>value</code> 的方式读取它。</p> <ul><li><code>placeholder</code> 值必须是字符串，不能是变量或表达式（服务端渲染或框架里需注意转义）</li> <li>中文空格、全角字符会导致显示异常，建议统一用半角空格</li> <li>不支持换行，<code><textarea placeholder="第一行第二行"></code> 中的 <code> </code> 会被忽略</li> <li>如果同时设了 <code>value</code> 和 <code>placeholder</code>，且 <code>value</code> 非空，那 <code>placeholder</code> 压根不显示</li> </ul><h3>React 里动态设置 <code>placeholder</code> 容易漏掉什么</h3> <p>JSX 中写 <code>placeholder={text}</code> 没问题，但要注意：当 <code>text</code> 是 <code>null</code> 或 <code>undefined</code> 时，React 会把属性完全省略，导致占位符消失——这和预期“显示空字符串提示”不符。</p> <ul><li>安全写法是显式转成字符串：<code>placeholder={text ?? ''}</code> 或 <code>placeholder={String(text)}</code></li> <li>如果依赖 props 或 state 动态更新，确认初始值不是 <code>undefined</code>，否则首次渲染无提示</li> <li>不要在 <code>placeholder</code> 里放敏感信息或实时校验结果，它只用于引导，不参与表单逻辑</li> </ul><h3>用 CSS 调整 <code>placeholder</code> 样式时的兼容性坑</h3> <p>各浏览器前缀不同，纯 CSS 修改颜色/字体大小必须覆盖所有主流写法，否则在 Safari 或旧版 Edge 里失效。</p> <pre class="brush:php;toolbar:false">input::placeholder, textarea::placeholder { color: #999; font-size: 14px; } input::-webkit-input-placeholder { color: #999; } input::-moz-placeholder { color: #999; } input:-ms-input-placeholder { color: #999; } textarea::-webkit-input-placeholder { color: #999; } textarea::-moz-placeholder { color: #999; } textarea:-ms-input-placeholder { color: #999; }</pre> <ul><li><code>::placeholder</code> 是标准语法，但 IE11 及更早版本只认 <code>::-ms-input-placeholder</code></li> <li>Firefox 中 <code>::-moz-placeholder</code> 会同时匹配空与非空状态，而 Chrome/Safari 的 <code>::-webkit-input-placeholder</code> 只在为空时生效</li> <li>别对 <code>placeholder</code> 做 <code>display: none</code>，部分安卓 WebView 会连输入框焦点都异常</li> </ul><h3>替代方案：什么时候不该用 <code>placeholder</code></h3> <p>WCAG 2.1 明确指出，仅靠 <code>placeholder</code> 无法满足可访问性要求——屏幕阅读器可能跳过它，且用户输入后提示就没了，容易忘记字段用途。</p> <ul><li>必填字段必须配 <code><label></code>，哪怕视觉上隐藏也要用 <code>aria-label</code> 或 <code>visually-hidden</code> 类</li> <li>复杂格式要求（如“手机号请输11位纯数字”）别塞进 <code>placeholder</code>，改用下方辅助文本 <code><small></code> 或 <code>aria-describedby</code></li> <li>多语言场景下，<code>placeholder</code> 很难做精准翻译缓存，不如由组件统一管理文案 key</li> </ul><p>真正要靠占位符引导的，只是最轻量的格式示意，比如“example@email.com”或“YYYY-MM-DD”。其余都该交给 label、hint 或实时反馈来承担。</p><p>理论要掌握，实操不能落！以上关于《输入框占位提示设置方法全解析》的详细介绍，大家都掌握了吧！如果想要继续提升自己的能力，那么就来关注golang学习网公众号吧！</p> </div> <div class="labsList"> <a href="javascript:;" class="aLightGray" title="html">html</a> </div> </div>  <div class="contBoxNor"> <div class="contTit"> <div class="tit">相关阅读</div> <a href="/articlelist.html" class="more">更多></a> </div> <ul class="latestReadList"> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 1年前 | <a href="javascript:;" class="aLightGray" title="提升">提升</a> <a href="javascript:;" class="aLightGray" title="箭头函数">箭头函数</a> <a href="javascript:;" class="aLightGray" title="函数表达式">函数表达式</a> <a href="javascript:;" class="aLightGray" title="函数声明">函数声明</a> <a href="javascript:;" class="aLightGray" title="Function构造函数">Function构造函数</a> </div> <div class="tit lineOverflow"><a href="/article/207000.html" title="JavaScript函数定义及示例详解" class="aBlack">JavaScript函数定义及示例详解</a></div> <div class="opt"> <span><i class="view"></i>502</span> <span class="collectBtn user_collection" data-id="207000" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 2年前 | <a href="javascript:;" class="aLightGray" title="CSS">CSS</a> <a href="javascript:;" class="aLightGray" title="优化">优化</a> <a href="javascript:;" class="aLightGray" title="体验">体验</a> </div> <div class="tit lineOverflow"><a href="/article/72840.html" title="优化用户界面体验的秘密武器：CSS开发项目经验大揭秘" class="aBlack">优化用户界面体验的秘密武器：CSS开发项目经验大揭秘</a></div> <div class="opt"> <span><i class="view"></i>501</span> <span class="collectBtn user_collection" data-id="72840" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 2年前 | <a href="javascript:;" class="aLightGray" title="图片轮播">图片轮播</a> <a href="javascript:;" class="aLightGray" title="微信小程序">微信小程序</a> <a href="javascript:;" class="aLightGray" title="特效">特效</a> </div> <div class="tit lineOverflow"><a href="/article/76259.html" title="使用微信小程序实现图片轮播特效" class="aBlack">使用微信小程序实现图片轮播特效</a></div> <div class="opt"> <span><i class="view"></i>501</span> <span class="collectBtn user_collection" data-id="76259" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 2年前 | <a href="javascript:;" class="aLightGray" title="sessionStorage">sessionStorage</a> <a href="javascript:;" class="aLightGray" title="存储能力">存储能力</a> <a href="javascript:;" class="aLightGray" title="限制解析">限制解析</a> </div> <div class="tit lineOverflow"><a href="/article/83771.html" title="解析sessionStorage的存储能力与限制" class="aBlack">解析sessionStorage的存储能力与限制</a></div> <div class="opt"> <span><i class="view"></i>501</span> <span class="collectBtn user_collection" data-id="83771" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 2年前 | <a href="javascript:;" class="aLightGray" title="团队合作">团队合作</a> <a href="javascript:;" class="aLightGray" title="冒泡事件">冒泡事件</a> <a href="javascript:;" class="aLightGray" title="促进作用">促进作用</a> </div> <div class="tit lineOverflow"><a href="/article/85057.html" title="探索冒泡活动对于团队合作的推动力" class="aBlack">探索冒泡活动对于团队合作的推动力</a></div> <div class="opt"> <span><i class="view"></i>501</span> <span class="collectBtn user_collection" data-id="85057" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> </ul> </div>  <div class="contBoxNor"> <div class="contTit"> <div class="tit">最新阅读</div> <a href="/articlelist.html" class="more">更多></a> </div> <ul class="latestReadList"> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 2天前 | <a href="/articletag/243_new_0_1.html" class="aLightGray" title="前端">前端</a> · <a href="/articletag/4720_new_0_1.html" class="aLightGray" title="cors">cors</a> · <a href="/articletag/39980_new_0_1.html" class="aLightGray" title="跨域排查">跨域排查</a> · <a href="/articletag/39981_new_0_1.html" class="aLightGray" title="浏览器网络">浏览器网络</a> · <a href="/articletag/39982_new_0_1.html" class="aLightGray" title="接口联调">接口联调</a> · <a href="javascript:;" class="aLightGray" title="前端">前端</a> <a href="javascript:;" class="aLightGray" title="cors">cors</a> <a href="javascript:;" class="aLightGray" title="请求头">请求头</a> <a href="javascript:;" class="aLightGray" title="跨域">跨域</a> <a href="javascript:;" class="aLightGray" title="预检请求">预检请求</a> <a href="javascript:;" class="aLightGray" title="Options">Options</a> </div> <div class="tit lineOverflow"><a href="/article/620039.html" title="前端 CORS 预检失败排查流程：从请求头到网关响应" class="aBlack">前端 CORS 预检失败排查流程：从请求头到网关响应</a></div> <div class="opt"> <span><i class="view"></i>422</span> <span class="collectBtn user_collection" data-id="620039" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 2天前 | <a href="/articletag/243_new_0_1.html" class="aLightGray" title="前端">前端</a> · <a href="/articletag/4729_new_0_1.html" class="aLightGray" title="css">css</a> · <a href="/articletag/9935_new_0_1.html" class="aLightGray" title="sticky">sticky</a> · <a href="/articletag/39972_new_0_1.html" class="aLightGray" title="布局排查">布局排查</a> · <a href="/articletag/39973_new_0_1.html" class="aLightGray" title="滚动容器">滚动容器</a> · <a href="javascript:;" class="aLightGray" title="CSS">CSS</a> <a href="javascript:;" class="aLightGray" title="前端">前端</a> <a href="javascript:;" class="aLightGray" title="Overflow">Overflow</a> <a href="javascript:;" class="aLightGray" title="position sticky">position sticky</a> <a href="javascript:;" class="aLightGray" title="滚动容器">滚动容器</a> <a href="javascript:;" class="aLightGray" title="吸顶失效">吸顶失效</a> </div> <div class="tit lineOverflow"><a href="/article/620035.html" title="前端 position sticky 不生效排查：从滚动容器到 overflow 限制" class="aBlack">前端 position sticky 不生效排查：从滚动容器到 overflow 限制</a></div> <div class="opt"> <span><i class="view"></i>449</span> <span class="collectBtn user_collection" data-id="620035" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 3天前 | <a href="/articletag/243_new_0_1.html" class="aLightGray" title="前端">前端</a> · <a href="/articletag/729_new_0_1.html" class="aLightGray" title="性能优化">性能优化</a> · <a href="/articletag/39948_new_0_1.html" class="aLightGray" title="图片加载">图片加载</a> · <a href="javascript:;" class="aLightGray" title="前端">前端</a> <a href="javascript:;" class="aLightGray" title="性能优化">性能优化</a> <a href="javascript:;" class="aLightGray" title="图片懒加载">图片懒加载</a> <a href="javascript:;" class="aLightGray" title="IntersectionObserver">IntersectionObserver</a> <a href="javascript:;" class="aLightGray" title="LCP">LCP</a> </div> <div class="tit lineOverflow"><a href="/article/620015.html" title="前端图片懒加载实战：首屏 LCP 与滚动加载完整流程" class="aBlack">前端图片懒加载实战：首屏 LCP 与滚动加载完整流程</a></div> <div class="opt"> <span><i class="view"></i>105</span> <span class="collectBtn user_collection" data-id="620015" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 3天前 | <a href="/articletag/243_new_0_1.html" class="aLightGray" title="前端">前端</a> · <a href="/articletag/729_new_0_1.html" class="aLightGray" title="性能优化">性能优化</a> · <a href="/articletag/39947_new_0_1.html" class="aLightGray" title="表单校验">表单校验</a> · <a href="javascript:;" class="aLightGray" title="JavaScript">JavaScript</a> <a href="javascript:;" class="aLightGray" title="前端">前端</a> <a href="javascript:;" class="aLightGray" title="表单校验">表单校验</a> <a href="javascript:;" class="aLightGray" title="重复提交">重复提交</a> <a href="javascript:;" class="aLightGray" title="提交锁">提交锁</a> </div> <div class="tit lineOverflow"><a href="/article/620013.html" title="前端表单联动校验失效排查：旧状态、重复提交和提交锁" class="aBlack">前端表单联动校验失效排查：旧状态、重复提交和提交锁</a></div> <div class="opt"> <span><i class="view"></i>285</span> <span class="collectBtn user_collection" data-id="620013" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 3天前 | <a href="/articletag/243_new_0_1.html" class="aLightGray" title="前端">前端</a> · <a href="/articletag/729_new_0_1.html" class="aLightGray" title="性能优化">性能优化</a> · <a href="/articletag/39783_new_0_1.html" class="aLightGray" title="虚拟列表">虚拟列表</a> · <a href="javascript:;" class="aLightGray" title="JavaScript">JavaScript</a> <a href="javascript:;" class="aLightGray" title="前端">前端</a> <a href="javascript:;" class="aLightGray" title="性能优化">性能优化</a> <a href="javascript:;" class="aLightGray" title="虚拟滚动">虚拟滚动</a> <a href="javascript:;" class="aLightGray" title="长列表优化">长列表优化</a> </div> <div class="tit lineOverflow"><a href="/article/620012.html" title="前端长列表虚拟滚动实战：从可视区计算到滚动流畅" class="aBlack">前端长列表虚拟滚动实战：从可视区计算到滚动流畅</a></div> <div class="opt"> <span><i class="view"></i>111</span> <span class="collectBtn user_collection" data-id="620012" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 4天前 | <a href="/articletag/215_new_0_1.html" class="aLightGray" title="定时器">定时器</a> · <a href="/articletag/243_new_0_1.html" class="aLightGray" title="前端">前端</a> · <a href="/articletag/39721_new_0_1.html" class="aLightGray" title="性能排查">性能排查</a> · <a href="/articletag/39918_new_0_1.html" class="aLightGray" title="接口请求">接口请求</a> · <a href="/articletag/39934_new_0_1.html" class="aLightGray" title="轮询">轮询</a> · <a href="/articletag/39935_new_0_1.html" class="aLightGray" title="setInterval">setInterval</a> · <a href="javascript:;" class="aLightGray" title="setInterval">setInterval</a> <a href="javascript:;" class="aLightGray" title="页面可见性">页面可见性</a> <a href="javascript:;" class="aLightGray" title="clearInterval">clearInterval</a> <a href="javascript:;" class="aLightGray" title="前端轮询">前端轮询</a> <a href="javascript:;" class="aLightGray" title="请求堆积">请求堆积</a> <a href="javascript:;" class="aLightGray" title="定时器清理">定时器清理</a> </div> <div class="tit lineOverflow"><a href="/article/619999.html" title="前端轮询接口越打越多怎么办：从重复定时器到清理机制一步步排查" class="aBlack">前端轮询接口越打越多怎么办：从重复定时器到清理机制一步步排查</a></div> <div class="opt"> <span><i class="view"></i>490</span> <span class="collectBtn user_collection" data-id="619999" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 4天前 | <a href="/articletag/243_new_0_1.html" class="aLightGray" title="前端">前端</a> · <a href="/articletag/39919_new_0_1.html" class="aLightGray" title="状态管理">状态管理</a> · <a href="/articletag/39920_new_0_1.html" class="aLightGray" title="表单提交">表单提交</a> · <a href="/articletag/39921_new_0_1.html" class="aLightGray" title="防重复提交">防重复提交</a> · <a href="/articletag/39922_new_0_1.html" class="aLightGray" title="接口幂等">接口幂等</a> · <a href="javascript:;" class="aLightGray" title="重复提交">重复提交</a> <a href="javascript:;" class="aLightGray" title="前端表单">前端表单</a> <a href="javascript:;" class="aLightGray" title="请求去重">请求去重</a> <a href="javascript:;" class="aLightGray" title="按钮锁定">按钮锁定</a> <a href="javascript:;" class="aLightGray" title="幂等key">幂等key</a> </div> <div class="tit lineOverflow"><a href="/article/619992.html" title="前端表单重复提交治理完整流程：按钮锁定、请求去重和幂等 key" class="aBlack">前端表单重复提交治理完整流程：按钮锁定、请求去重和幂等 key</a></div> <div class="opt"> <span><i class="view"></i>253</span> <span class="collectBtn user_collection" data-id="619992" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 4天前 | <a href="/articletag/243_new_0_1.html" class="aLightGray" title="前端">前端</a> · <a href="/articletag/39916_new_0_1.html" class="aLightGray" title="搜索框">搜索框</a> · <a href="/articletag/39917_new_0_1.html" class="aLightGray" title="AbortController">AbortController</a> · <a href="/articletag/39918_new_0_1.html" class="aLightGray" title="接口请求">接口请求</a> · <a href="/articletag/39919_new_0_1.html" class="aLightGray" title="状态管理">状态管理</a> · <a href="javascript:;" class="aLightGray" title="Fetch">Fetch</a> <a href="javascript:;" class="aLightGray" title="AbortController">AbortController</a> <a href="javascript:;" class="aLightGray" title="前端搜索">前端搜索</a> <a href="javascript:;" class="aLightGray" title="请求乱序">请求乱序</a> <a href="javascript:;" class="aLightGray" title="旧响应覆盖">旧响应覆盖</a> </div> <div class="tit lineOverflow"><a href="/article/619990.html" title="前端搜索结果倒退怎么办：AbortController 取消旧请求和序号兜底" class="aBlack">前端搜索结果倒退怎么办：AbortController 取消旧请求和序号兜底</a></div> <div class="opt"> <span><i class="view"></i>295</span> <span class="collectBtn user_collection" data-id="619990" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 5天前 | <a href="/articletag/243_new_0_1.html" class="aLightGray" title="前端">前端</a> · <a href="/articletag/729_new_0_1.html" class="aLightGray" title="性能优化">性能优化</a> · <a href="/articletag/34073_new_0_1.html" class="aLightGray" title="cls">cls</a> · <a href="/articletag/39909_new_0_1.html" class="aLightGray" title="懒加载">懒加载</a> · <a href="/articletag/39910_new_0_1.html" class="aLightGray" title="Core Web Vitals">Core Web Vitals</a> · <a href="javascript:;" class="aLightGray" title="前端">前端</a> <a href="javascript:;" class="aLightGray" title="图片懒加载">图片懒加载</a> <a href="javascript:;" class="aLightGray" title="IntersectionObserver">IntersectionObserver</a> <a href="javascript:;" class="aLightGray" title="CLS">CLS</a> <a href="javascript:;" class="aLightGray" title="布局稳定">布局稳定</a> </div> <div class="tit lineOverflow"><a href="/article/619979.html" title="前端图片懒加载布局抖动治理完整流程：占位比例、按需加载和 CLS 复查" class="aBlack">前端图片懒加载布局抖动治理完整流程：占位比例、按需加载和 CLS 复查</a></div> <div class="opt"> <span><i class="view"></i>128</span> <span class="collectBtn user_collection" data-id="619979" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 5天前 | <a href="/articletag/243_new_0_1.html" class="aLightGray" title="前端">前端</a> · <a href="/articletag/277_new_0_1.html" class="aLightGray" title="消息队列">消息队列</a> · <a href="/articletag/1017_new_0_1.html" class="aLightGray" title="websocket">websocket</a> · <a href="/articletag/39899_new_0_1.html" class="aLightGray" title="实时通信">实时通信</a> · <a href="/articletag/39900_new_0_1.html" class="aLightGray" title="断线重连">断线重连</a> · <a href="javascript:;" class="aLightGray" title="前端">前端</a> <a href="javascript:;" class="aLightGray" title="websocket">websocket</a> <a href="javascript:;" class="aLightGray" title="心跳检测">心跳检测</a> <a href="javascript:;" class="aLightGray" title="断线重连">断线重连</a> <a href="javascript:;" class="aLightGray" title="消息补发">消息补发</a> </div> <div class="tit lineOverflow"><a href="/article/619973.html" title="前端 WebSocket 断线重连完整流程：心跳检测、退避重试和消息补发" class="aBlack">前端 WebSocket 断线重连完整流程：心跳检测、退避重试和消息补发</a></div> <div class="opt"> <span><i class="view"></i>365</span> <span class="collectBtn user_collection" data-id="619973" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 5天前 | <a href="/articletag/228_new_0_1.html" class="aLightGray" title="工程化">工程化</a> · <a href="/articletag/243_new_0_1.html" class="aLightGray" title="前端">前端</a> · <a href="/articletag/4701_new_0_1.html" class="aLightGray" title="javascript">javascript</a> · <a href="/articletag/4729_new_0_1.html" class="aLightGray" title="css">css</a> · <a href="/articletag/39876_new_0_1.html" class="aLightGray" title="弹窗">弹窗</a> · <a href="javascript:;" class="aLightGray" title="前端">前端</a> <a href="javascript:;" class="aLightGray" title="z-index">z-index</a> <a href="javascript:;" class="aLightGray" title="遮罩层">遮罩层</a> <a href="javascript:;" class="aLightGray" title="stacking context">stacking context</a> <a href="javascript:;" class="aLightGray" title="Portal">Portal</a> <a href="javascript:;" class="aLightGray" title="弹窗层级">弹窗层级</a> </div> <div class="tit lineOverflow"><a href="/article/619962.html" title="前端弹窗层级治理工作流：从 z-index 混乱到 Portal 容器规范" class="aBlack">前端弹窗层级治理工作流：从 z-index 混乱到 Portal 容器规范</a></div> <div class="opt"> <span><i class="view"></i>350</span> <span class="collectBtn user_collection" data-id="619962" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> <li> <div class="info"> <a href="/articlelist/19_new_0_1.html" class="aLightGray" title="文章">文章</a> · <a href="/articlelist/88_new_0_1.html" class="aLightGray" title="前端">前端</a> | 5天前 | <a href="/articletag/243_new_0_1.html" class="aLightGray" title="前端">前端</a> · <a href="/articletag/4701_new_0_1.html" class="aLightGray" title="javascript">javascript</a> · <a href="/articletag/39873_new_0_1.html" class="aLightGray" title="URL参数">URL参数</a> · <a href="/articletag/39874_new_0_1.html" class="aLightGray" title="列表筛选">列表筛选</a> · <a href="/articletag/39875_new_0_1.html" class="aLightGray" title="页面状态">页面状态</a> · <a href="javascript:;" class="aLightGray" title="前端">前端</a> <a href="javascript:;" class="aLightGray" title="筛选条件">筛选条件</a> <a href="javascript:;" class="aLightGray" title="列表页">列表页</a> <a href="javascript:;" class="aLightGray" title="history.replaceState">history.replaceState</a> <a href="javascript:;" class="aLightGray" title="URLSearchParams">URLSearchParams</a> <a href="javascript:;" class="aLightGray" title="刷新还原">刷新还原</a> </div> <div class="tit lineOverflow"><a href="/article/619961.html" title="前端筛选条件刷新后丢失怎么办：从内存状态到 URL 参数一步步排查" class="aBlack">前端筛选条件刷新后丢失怎么办：从内存状态到 URL 参数一步步排查</a></div> <div class="opt"> <span><i class="view"></i>348</span> <span class="collectBtn user_collection" data-id="619961" data-type="article" title="收藏"><i class="collect"></i>收藏</span> </div> </li> </ul> </div>  <div class="contBoxNor"> <div class="contTit"> <div class="tit">课程推荐</div> <a href="/courselist.html" class="more">更多></a> </div> <ul class="classRecomList"> <li> <a href="/course/9.html" title="前端进阶之JavaScript设计模式" class="img_box"> <img src="/uploads/20221222/52fd0f23a454c71029c2c72d206ed815.jpg" onerror="this.onerror='';this.src='/assets/images/moren/morentu.png'" alt="前端进阶之JavaScript设计模式"> </a> <dl> <dt class="lineOverflow"> 前端进阶之JavaScript设计模式 </dt> <dd class="cont1 lineOverflow">设计模式是开发人员在软件开发过程中面临一般问题时的解决方案，代表了最佳的实践。本课程的主打内容包括JS常见设计模式以及具体应用场景，打造一站式知识长龙服务，适合有JS基础的同学学习。</dd> <dd class="cont2"> <a href="/course/9.html" title="前端进阶之JavaScript设计模式" class="toStudy">立即学习</a> <span>543次学习</span> </dd> </dl> </li> <li> <a href="/course/2.html" title="GO语言核心编程课程" class="img_box"> <img src="/uploads/20221221/634ad7404159bfefc6a54a564d437b5f.png" onerror="this.onerror='';this.src='/assets/images/moren/morentu.png'" alt="GO语言核心编程课程"> </a> <dl> <dt class="lineOverflow"> GO语言核心编程课程 </dt> <dd class="cont1 lineOverflow">本课程采用真实案例，全面具体可落地，从理论到实践，一步一步将GO核心编程技术、编程思想、底层实现融会贯通，使学习者贴近时代脉搏，做IT互联网时代的弄潮儿。</dd> <dd class="cont2"> <a href="/course/2.html" title="GO语言核心编程课程" class="toStudy">立即学习</a> <span>516次学习</span> </dd> </dl> </li> <li> <a href="/course/74.html" title="简单聊聊mysql8与网络通信" class="img_box"> <img src="/uploads/20240103/bad35fe14edbd214bee16f88343ac57c.png" onerror="this.onerror='';this.src='/assets/images/moren/morentu.png'" alt="简单聊聊mysql8与网络通信"> </a> <dl> <dt class="lineOverflow"> 简单聊聊mysql8与网络通信 </dt> <dd class="cont1 lineOverflow">如有问题加微信：Le-studyg；在课程中，我们将首先介绍MySQL8的新特性，包括性能优化、安全增强、新数据类型等，帮助学生快速熟悉MySQL8的最新功能。接着，我们将深入解析MySQL的网络通信机制，包括协议、连接管理、数据传输等，让</dd> <dd class="cont2"> <a href="/course/74.html" title="简单聊聊mysql8与网络通信" class="toStudy">立即学习</a> <span>500次学习</span> </dd> </dl> </li> <li> <a href="/course/57.html" title="JavaScript正则表达式基础与实战" class="img_box"> <img src="/uploads/20221226/bbe4083bb3cb0dd135fb02c31c3785fb.jpg" onerror="this.onerror='';this.src='/assets/images/moren/morentu.png'" alt="JavaScript正则表达式基础与实战"> </a> <dl> <dt class="lineOverflow"> JavaScript正则表达式基础与实战 </dt> <dd class="cont1 lineOverflow">在任何一门编程语言中,正则表达式,都是一项重要的知识,它提供了高效的字符串匹配与捕获机制,可以极大的简化程序设计。</dd> <dd class="cont2"> <a href="/course/57.html" title="JavaScript正则表达式基础与实战" class="toStudy">立即学习</a> <span>487次学习</span> </dd> </dl> </li> <li> <a href="/course/28.html" title="从零制作响应式网站—Grid布局" class="img_box"> <img src="/uploads/20221223/ac110f88206daeab6c0cf38ebf5fe9ed.jpg" onerror="this.onerror='';this.src='/assets/images/moren/morentu.png'" alt="从零制作响应式网站—Grid布局"> </a> <dl> <dt class="lineOverflow"> 从零制作响应式网站—Grid布局 </dt> <dd class="cont1 lineOverflow">本系列教程将展示从零制作一个假想的网络科技公司官网，分为导航，轮播，关于我们，成功案例，服务流程，团队介绍，数据部分，公司动态，底部信息等内容区块。网站整体采用CSSGrid布局，支持响应式，有流畅过渡和展现动画。</dd> <dd class="cont2"> <a href="/course/28.html" title="从零制作响应式网站—Grid布局" class="toStudy">立即学习</a> <span>485次学习</span> </dd> </dl> </li> </ul> </div> </div>  <div class="footer"> <ul> <li ><a href="/" class="aLightGray"><em class="navIcon navIconHome"></em><span>首页</span></a></li> <li class="curr"><a href="/articlelist.html" class="aLightGray"><em class="navIcon navIconRead"></em><span>阅读</span></a></li> <li ><a href="/courselist.html" class="aLightGray"><em class="navIcon navIconCourse"></em><span>课程</span></a></li> <li ><a href="/ai.html" class="aLightGray"><em class="navIcon navIconAi"></em><span>AI助手</span></a></li> <li ><a href="/user.html" class="aLightGray"><em class="navIcon navIconUser"></em><span>我的</span></a></li> </ul> </div> <script src="/assets/js/frontend/common.js" defer></script> <script src="/assets/js/juejin-theme.js?v=20260613b" defer></script> <script> var _hmt = _hmt || []; (function() { var hm = document.createElement("script"); hm.src = "https://hm.baidu.com/hm.js?3dc5666f6478c7bf39cd5c91e597423d"; hm.async = true; var s = document.getElementsByTagName("script")[0]; s.parentNode.insertBefore(hm, s); })(); </script> </body> </html>

输入框占位提示设置方法全解析

HTML 中 placeholder 属性怎么写才有效

HTML 中 `placeholder` 属性怎么写才有效