I\'m trying to validate the content of a </code> using JavaScript, So I created a <code>validate()</code> function, which returns <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script> <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-5408099190056760" data-ad-slot="7305827575" data-ad-format="auto" data-full-width-responsive="true"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> <div class="relativetags"> 相关标签: </div> </div> <div class="fly-panel detail-box" id="flyReply"> <fieldset class="layui-elem-field layui-field-title" style="text-align: center;"> <legend>6条回答</legend> </fieldset> <ul class="jieda" id="jieda"> <li data-id="111"> <a name="item-1111111111"></a> <div class="detail-about detail-about-reply"> <a class="fly-avatar" href="https://www.e-learn.cn/qa/u-77.html"> <img src="https://www.e-learn.cn/qa/data/avatar/000/00/00/small_000000077.jpg" alt=" "> </a> <div class="fly-detail-user"> <a href="https://www.e-learn.cn/qa/u-77.html" class="fly-link"> <cite>粉色の甜心 </cite> </a> </div> <div class="detail-hits"> <span>2021-01-07 04:38</span> </div> </div> <div class="detail-body jieda-body photos"> <p>The answers saying to not use regex are perfectly fine, but I like regex so:</p> <pre><code>^\s*(?:(?:\w+(?:-+\w+)*\.)+[a-z]+)\s*(?:,\s*(?:(?:\w+(?:-+\w+)*\.)+[a-z]+)\s*)*$ </code></pre> <p>Yeah..it's not so pretty. But it works - tested on your sample cases at http://regex101.com</p> <p>Edit: OK let's break it down. And only allow <code>sub-domain-01.com</code> and <code>a--b.com</code> and not <code>-.com</code></p> <p>Each subdomain thingo: <code>\w+(?:-+\w+)*</code> matches string of word characters plus optionally some words with dashes preceeding it.</p> <p>Each hostname: <code>\s*(?:(?:\w+(?:-\w+)*\.)+[a-z]+)\s*</code> a bunch of subdomain thingos followed by a dot. Then finally followed by a string of letters only (the tld). And of course the optional spaces around the sides.</p> <p>Whole thing: <code>\s*(?:(?:\w+(?:-\w+)*\.)+[a-z]+)\s*(?:,\s*(?:(?:\w+(?:-\w+)*\.)+[a-z]+)\s*)*</code> a single hostname, followed by 0 or more <code>,hostname</code>s for our comma separated list.</p> <p>Pretty simple really.</p> <div class="appendcontent"> </div> </div> <div class="jieda-reply"> <span class="jieda-zan button_agree" type="zan" data-id='1648744'> <i class="iconfont icon-zan"></i> <em>0</em> </span> <span type="reply" class="showpinglun" data-id="1648744"> <i class="iconfont icon-svgmoban53"></i> 讨论(0) </span> <div class="jieda-admin"> </div> </div> <div class="comments-mod " style="display: none; float:none;padding-top:10px;" id="comment_1648744"> <div class="areabox clearfix"> <form class="layui-form" action=""> <div class="layui-form-item"> <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label> <div class="layui-input-block" style="margin-left:90px;"> <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" /> <input type='hidden' value='0' name='replyauthor' /> </div> <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1648744">提交评论 </span></div> </div> </form> </div> <hr> <ul class="my-comments-list nav"> <li class="loading"> <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' /> 加载中... </li> </ul> </div> </li> <li data-id="111"> <a name="item-1111111111"></a> <div class="detail-about detail-about-reply"> <a class="fly-avatar" href="https://www.e-learn.cn/qa/u-45.html"> <img src="https://www.e-learn.cn/qa/data/avatar/000/00/00/small_000000045.jpg" alt=" "> </a> <div class="fly-detail-user"> <a href="https://www.e-learn.cn/qa/u-45.html" class="fly-link"> <cite>耶瑟儿～ </cite> </a> </div> <div class="detail-hits"> <span>2021-01-07 04:38</span> </div> </div> <div class="detail-body jieda-body photos"> <pre><code>function validate() { //Get the user input var hostnames = document.getElementById('yourtextarea').value; //Regex to validate hostname var re = new RegExp(/^([a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,6}$/); //Trim whitespace hostnames = hostnames.trim(); //Explode into an array hostnames = hostnames.split(","); //Loop through array & test each hostname with regex var is_valid = true; for (var i=0; i < hostnames.length; i++){ var hostname = hostnames[i].trim(); if (re.test(hostname)) { is_valid = true; //if valid, continue loop } else { is_valid = false; //if invalid, break loop and return false break; } } //end for loop return is_valid; } //end function validate() </code></pre> <p>Matches every example you indicated except "dom-ain.it, domain.com, domain.eu.org.something" because "something" is not valid.</p> <p>JSFiddle: http://jsfiddle.net/nesutqjf/2/</p> <div class="appendcontent"> </div> </div> <div class="jieda-reply"> <span class="jieda-zan button_agree" type="zan" data-id='1648746'> <i class="iconfont icon-zan"></i> <em>0</em> </span> <span type="reply" class="showpinglun" data-id="1648746"> <i class="iconfont icon-svgmoban53"></i> 讨论(0) </span> <div class="jieda-admin"> </div> </div> <div class="comments-mod " style="display: none; float:none;padding-top:10px;" id="comment_1648746"> <div class="areabox clearfix"> <form class="layui-form" action=""> <div class="layui-form-item"> <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label> <div class="layui-input-block" style="margin-left:90px;"> <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" /> <input type='hidden' value='0' name='replyauthor' /> </div> <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1648746">提交评论 </span></div> </div> </form> </div> <hr> <ul class="my-comments-list nav"> <li class="loading"> <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' /> 加载中... </li> </ul> </div> </li> <li data-id="111"> <a name="item-1111111111"></a> <div class="detail-about detail-about-reply"> <a class="fly-avatar" href="https://www.e-learn.cn/qa/u-26.html"> <img src="https://www.e-learn.cn/qa/data/avatar/000/00/00/small_000000026.jpg" alt=" "> </a> <div class="fly-detail-user"> <a href="https://www.e-learn.cn/qa/u-26.html" class="fly-link"> <cite>星月不相逢 </cite> </a> </div> <div class="detail-hits"> <span>2021-01-07 04:43</span> </div> </div> <div class="detail-body jieda-body photos"> <p>I would not use regexps for this, because you have a <strong>lot</strong> of different rules you want to check. Regexps are good when you only have a couple of rules that are very simple to express but a pain to write out as "parsing code".</p> <p>I'd simply do <code>hostnames.split(',').forEach(validateHostname);</code>, as most of the comments suggest, and inside <code>validateHostname</code> reject any hostname that has spaces in the middle, two adjacent dots, no dots, ends in a dot, has non-ASCII characters, has digits in the last dot-separated token, and so on and so forth.</p> <p>A function like this will be much easier to add new rules to than a regexp would be.</p> <div class="appendcontent"> </div> </div> <div class="jieda-reply"> <span class="jieda-zan button_agree" type="zan" data-id='1648747'> <i class="iconfont icon-zan"></i> <em>0</em> </span> <span type="reply" class="showpinglun" data-id="1648747"> <i class="iconfont icon-svgmoban53"></i> 讨论(0) </span> <div class="jieda-admin"> </div> </div> <div class="comments-mod " style="display: none; float:none;padding-top:10px;" id="comment_1648747"> <div class="areabox clearfix"> <form class="layui-form" action=""> <div class="layui-form-item"> <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label> <div class="layui-input-block" style="margin-left:90px;"> <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" /> <input type='hidden' value='0' name='replyauthor' /> </div> <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1648747">提交评论 </span></div> </div> </form> </div> <hr> <ul class="my-comments-list nav"> <li class="loading"> <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' /> 加载中... </li> </ul> </div> </li> <li data-id="111"> <a name="item-1111111111"></a> <div class="detail-about detail-about-reply"> <a class="fly-avatar" href="https://www.e-learn.cn/qa/u-99.html"> <img src="https://www.e-learn.cn/qa/data/avatar/000/00/00/small_000000099.jpg" alt=" "> </a> <div class="fly-detail-user"> <a href="https://www.e-learn.cn/qa/u-99.html" class="fly-link"> <cite>忘掉有多难 </cite> </a> </div> <div class="detail-hits"> <span>2021-01-07 04:44</span> </div> </div> <div class="detail-body jieda-body photos"> <p>An example with validate.js which has well tested routines for testing a valid FQDN. Alternatively look through the source and grab what you need.</p> <p><div class="snippet" data-lang="js" data-hide="false"> <div class="snippet-code"> <pre class="snippet-code-js lang-js prettyprint-override"><code>function validate (e) { var target = e.target || e; target.value.split(',').some(function (item) { var notValid = !validator.isFQDN(item.trim()); if (notValid) { target.classList.add('bad'); } else { target.classList.remove('bad'); } return notValid; }); } var domains = document.getElementById('domains'); domains.addEventListener('change', validate); validate(domains);</code></pre> <pre class="snippet-code-css lang-css prettyprint-override"><code>#domains { width: 300px; height: 100px; } .bad { background-color: red }</code></pre> <pre class="snippet-code-html lang-html prettyprint-override"><code><script src="http://rawgit.com/chriso/validator.js/master/validator.js"></script> <textarea id="domains">www.example.com, example.com, example.ca, example, example.com example.nl www.example, www.exam ple.com</textarea></code></pre> </div> </div> </p> <div class="appendcontent"> </div> </div> <div class="jieda-reply"> <span class="jieda-zan button_agree" type="zan" data-id='1648749'> <i class="iconfont icon-zan"></i> <em>0</em> </span> <span type="reply" class="showpinglun" data-id="1648749"> <i class="iconfont icon-svgmoban53"></i> 讨论(0) </span> <div class="jieda-admin"> </div> </div> <div class="comments-mod " style="display: none; float:none;padding-top:10px;" id="comment_1648749"> <div class="areabox clearfix"> <form class="layui-form" action=""> <div class="layui-form-item"> <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label> <div class="layui-input-block" style="margin-left:90px;"> <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" /> <input type='hidden' value='0' name='replyauthor' /> </div> <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1648749">提交评论 </span></div> </div> </form> </div> <hr> <ul class="my-comments-list nav"> <li class="loading"> <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' /> 加载中... </li> </ul> </div> </li> <li data-id="111"> <a name="item-1111111111"></a> <div class="detail-about detail-about-reply"> <a class="fly-avatar" href="https://www.e-learn.cn/qa/u-26.html"> <img src="https://www.e-learn.cn/qa/data/avatar/000/00/00/small_000000026.jpg" alt=" "> </a> <div class="fly-detail-user"> <a href="https://www.e-learn.cn/qa/u-26.html" class="fly-link"> <cite>星月不相逢 </cite> </a> </div> <div class="detail-hits"> <span>2021-01-07 04:49</span> </div> </div> <div class="detail-body jieda-body photos"> <p>I have been using this pattern for awhile, and seems to be working for your case, too:</p> <pre><code>/^[a-zA-Z0-9][a-zA-Z0-9\-_]*\.([a-zA-Z0-9]+|[a-zA-Z0-9\-_]+\.[a-zA-Z]+)+$/gi </code></pre> <p>The logic is simple:</p> <ul> <li><code>^[a-zA-Z0-9]</code>: The URL must start with an alphanumeric character</li> <li><code>[a-zA-Z0-9\-_]*</code>: The first alphanumeric character can be followed by zero or more of: an alphanumeric character, an underscore or a dash</li> <li><code>\.</code>: The first piece must be followed by a period.</li> <li>The second piece must follow the same pattern: <ol> <li><code>[a-zA-Z0-9]+</code>: One or more alphanumeric character, OR</li> <li><code>[a-zA-Z0-9\-_]+\.[a-zA-Z0-9]+</code>: One or more alphanumeric character, an underscore or a dash followed by a period and one or more alphanumeric character</li> </ol></li> </ul> <p>You can check this pattern working for most of your URLs in the following code snippet. How I do it is similar to the strategy described by others:</p> <ul> <li>Get the value of the textarea on keyup (or you can bind the submit, blur, keypress, keydown, change and etc)</li> <li>Split the value by the <code>,</code> character</li> <li>Use <code>$.trim()</code> to remove flanking whitespaces</li> <li>Use the RegEx pattern above to evaluate each individual string</li> </ul> <p>Optional, done for visual output:</p> <ul> <li>Generate a list of URLs</li> <li>Indicate if each URL entered is valid or not</li> </ul> <p><div class="snippet" data-lang="js" data-hide="false"> <div class="snippet-code"> <pre class="snippet-code-js lang-js prettyprint-override"><code>$(function() { $('textarea').keyup(function() { var urls = $(this).val().split(','); $('ul').empty(); $.each(urls, function(i,v) { // Trim URL var url = $.trim(v); // RegEx var pat = /^[a-zA-Z0-9][a-zA-Z0-9\-_]*\.([a-zA-Z0-9]+|[a-zA-Z0-9\-_]+\.[a-zA-Z]+)+$/gi, test = pat.test(url); // Append $('ul').append('<li>'+url+' <span>'+test+'</span></li>'); }); }); });</code></pre> <pre class="snippet-code-css lang-css prettyprint-override"><code>textarea { width: 100%; height: 100px; } ul span { background-color: #eee; display: inline-block; margin-left: .25em; padding: 0 .25em; text-transform: uppercase; }</code></pre> <pre class="snippet-code-html lang-html prettyprint-override"><code><script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <textarea placeholder="Paste URLs here"></textarea> <ul></ul></code></pre> </div> </div> </p> <div class="appendcontent"> </div> </div> <div class="jieda-reply"> <span class="jieda-zan button_agree" type="zan" data-id='1648748'> <i class="iconfont icon-zan"></i> <em>0</em> </span> <span type="reply" class="showpinglun" data-id="1648748"> <i class="iconfont icon-svgmoban53"></i> 讨论(0) </span> <div class="jieda-admin"> </div> </div> <div class="comments-mod " style="display: none; float:none;padding-top:10px;" id="comment_1648748"> <div class="areabox clearfix"> <form class="layui-form" action=""> <div class="layui-form-item"> <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label> <div class="layui-input-block" style="margin-left:90px;"> <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" /> <input type='hidden' value='0' name='replyauthor' /> </div> <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1648748">提交评论 </span></div> </div> </form> </div> <hr> <ul class="my-comments-list nav"> <li class="loading"> <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' /> 加载中... </li> </ul> </div> </li> <li data-id="111"> <a name="item-1111111111"></a> <div class="detail-about detail-about-reply"> <a class="fly-avatar" href="https://www.e-learn.cn/qa/u-43.html"> <img src="https://www.e-learn.cn/qa/data/avatar/000/00/00/small_000000043.jpg" alt=" "> </a> <div class="fly-detail-user"> <a href="https://www.e-learn.cn/qa/u-43.html" class="fly-link"> <cite>小蘑菇 </cite> </a> </div> <div class="detail-hits"> <span>2021-01-07 04:58</span> </div> </div> <div class="detail-body jieda-body photos"> <p>While @dandavis's answer/comment is impressive, lets break it down in to steps.</p> <ol> <li>Get the value from the textarea and <code>trim()</code> leading and ending spaces.</li> <li>Replace all white spaces with a single white space using <code>/\s+/g</code>. meaning find every white space occurring one or more times.</li> <li>Split by <code>,<space></code> or <code><space>,<space></code>. Split returns array.</li> <li>Iterate every array element with filter</li> <li>Check if element is a valid domain. If so return it.</li> </ol> <p><div class="snippet" data-lang="js" data-hide="false"> <div class="snippet-code"> <pre class="snippet-code-js lang-js prettyprint-override"><code>var domains = document.querySelector("textarea").value; domains = domains.trim().replace(/\s+/g, " ").split(/\s?,\s/); var domainsTested = domains.filter(function(element){ if (element.match(/^[a-zA-Z0-9][a-zA-Z0-9-_]{0,61}[a-zA-Z0-9]{0,1}\.([a-zA-Z]{1,6}|[a-zA-Z0-9-]{1,30}\.[a-zA-Z]{2,3})$/)) { return element; } }) document.write(domainsTested.join(" | ")); //this is just here to show the results. document.write("<br />Domainstring is ok: " + (domainsTested.length == domains.length)); //If it's valid then this should be equal.</code></pre> <pre class="snippet-code-html lang-html prettyprint-override"><code><textarea style="width: 300px; height: 100px">www.example.com , example.com, example.ca, example, example.com example.nl www.example, www.exam ple.com, sub.sub.sub.domain.tv, do main.it, sub.domain.tv</textarea></code></pre> </div> </div> </p> <div class="appendcontent"> </div> </div> <div class="jieda-reply"> <span class="jieda-zan button_agree" type="zan" data-id='1648745'> <i class="iconfont icon-zan"></i> <em>0</em> </span> <span type="reply" class="showpinglun" data-id="1648745"> <i class="iconfont icon-svgmoban53"></i> 讨论(0) </span> <div class="jieda-admin"> </div> </div> <div class="comments-mod " style="display: none; float:none;padding-top:10px;" id="comment_1648745"> <div class="areabox clearfix"> <form class="layui-form" action=""> <div class="layui-form-item"> <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label> <div class="layui-input-block" style="margin-left:90px;"> <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" /> <input type='hidden' value='0' name='replyauthor' /> </div> <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1648745">提交评论 </span></div> </div> </form> </div> <hr> <ul class="my-comments-list nav"> <li class="loading"> <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' /> 加载中... </li> </ul> </div> </li> <style> .laypage-main a, .laypage-main span { display: inline-block; } </style> </ul> <div class="layui-form layui-form-pane"> <form id="huidaform" name="answerForm" method="post"> <div class="layui-form-item layui-form-text"> <a name="comment"></a> <div class="layui-input-block"> <script type="text/javascript" src="https://www.e-learn.cn/qa/static/js/neweditor/ueditor.config.js"></script> <script type="text/javascript" src="https://www.e-learn.cn/qa/static/js/neweditor/ueditor.all.js"></script> <script type="text/plain" id="editor" name="content" style="width:100%;height:200px;"></script> <script type="text/javascript"> var isueditor=1; var editor = UE.getEditor('editor',{ //这里可以选择自己需要的工具按钮名称,此处仅选择如下五个 toolbars:[['source','fullscreen', '|', 'undo', 'redo', '|', 'bold', 'italic', 'underline', 'fontborder', 'strikethrough', 'removeformat', 'formatmatch', 'autotypeset', 'blockquote', 'pasteplain', '|', 'forecolor', 'backcolor', 'insertorderedlist', 'insertunorderedlist', 'selectall', 'cleardoc', '|', 'rowspacingtop', 'rowspacingbottom', 'lineheight', '|', 'customstyle', 'paragraph', 'fontfamily', 'fontsize', '|', 'indent', '|', 'justifyleft', 'justifycenter', 'justifyright', 'justifyjustify', '|', 'link', 'unlink', 'anchor', '|', 'simpleupload', 'insertimage', 'scrawl', 'insertvideo', 'attachment', 'map', 'insertcode', '|', 'horizontal', '|', 'preview', 'searchreplace', 'drafts']], initialContent:'', //关闭字数统计 wordCount:false, zIndex:2, //关闭elementPath elementPathEnabled:false, //默认的编辑区域高度 initialFrameHeight:250 //更多其他参数，请参考ueditor.config.js中的配置项 //更多其他参数，请参考ueditor.config.js中的配置项 }); editor.ready(function() { editor.setDisabled(); }); $("#editor").find("*").css("max-width","362px"); </script> </div> </div> <div class="layui-form-item"> <label for="L_vercode" class="layui-form-label">验证码</label> <div class="layui-input-inline"> <input type="text" id="code" name="code" value="" required lay-verify="required" placeholder="图片验证码" autocomplete="off" class="layui-input"> </div> <div class="layui-form-mid"> <span style="color: #c00;"><img class="hand" src="https://www.e-learn.cn/qa/user/code.html" onclick="javascript:updatecode();" id="verifycode"><a class="changecode" href="javascript:updatecode();"> 看不清?</a></span> </div> </div> <div class="layui-form-item"> <input type="hidden" value="682480" id="ans_qid" name="qid"> <input type="hidden" id="tokenkey" name="tokenkey" value=''/> <input type="hidden" value="RegExp to match comma separated hostnames" id="ans_title" name="title"> <div class="layui-btn layui-btn-disabled" id="ajaxsubmitasnwer" >提交回复</div> </div> </form> </div> </div> <input type="hidden" value="682480" id="adopt_qid" name="qid" /> <input type="hidden" id="adopt_answer" value="0" name="aid" /> </div> <div class="layui-col-md4"> <!-- 热门讨论问题 --> <dl class="fly-panel fly-list-one"> <dt class="fly-panel-title">热议问题</dt> <!-- 本周热门讨论问题显示10条-->
</code> using JavaScript, So I created a <code>validate()</code> function, which returns <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script> <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-5408099190056760" data-ad-slot="7305827575" data-ad-format="auto" data-full-width-responsive="true"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> <div class="relativetags"> 相关标签: </div> </div> <div class="fly-panel detail-box" id="flyReply"> <fieldset class="layui-elem-field layui-field-title" style="text-align: center;"> <legend>6条回答</legend> </fieldset> <ul class="jieda" id="jieda"> <li data-id="111"> <a name="item-1111111111"></a> <div class="detail-about detail-about-reply"> <a class="fly-avatar" href="https://www.e-learn.cn/qa/u-77.html"> <img src="https://www.e-learn.cn/qa/data/avatar/000/00/00/small_000000077.jpg" alt=" "> </a> <div class="fly-detail-user"> <a href="https://www.e-learn.cn/qa/u-77.html" class="fly-link"> <cite>粉色の甜心 </cite> </a> </div> <div class="detail-hits"> <span>2021-01-07 04:38</span> </div> </div> <div class="detail-body jieda-body photos"> <p>The answers saying to not use regex are perfectly fine, but I like regex so:</p> <pre><code>^\s*(?:(?:\w+(?:-+\w+)*\.)+[a-z]+)\s*(?:,\s*(?:(?:\w+(?:-+\w+)*\.)+[a-z]+)\s*)*$ </code></pre> <p>Yeah..it's not so pretty. But it works - tested on your sample cases at http://regex101.com</p> <p>Edit: OK let's break it down. And only allow <code>sub-domain-01.com</code> and <code>a--b.com</code> and not <code>-.com</code></p> <p>Each subdomain thingo: <code>\w+(?:-+\w+)*</code> matches string of word characters plus optionally some words with dashes preceeding it.</p> <p>Each hostname: <code>\s*(?:(?:\w+(?:-\w+)*\.)+[a-z]+)\s*</code> a bunch of subdomain thingos followed by a dot. Then finally followed by a string of letters only (the tld). And of course the optional spaces around the sides.</p> <p>Whole thing: <code>\s*(?:(?:\w+(?:-\w+)*\.)+[a-z]+)\s*(?:,\s*(?:(?:\w+(?:-\w+)*\.)+[a-z]+)\s*)*</code> a single hostname, followed by 0 or more <code>,hostname</code>s for our comma separated list.</p> <p>Pretty simple really.</p> <div class="appendcontent"> </div> </div> <div class="jieda-reply"> <span class="jieda-zan button_agree" type="zan" data-id='1648744'> <i class="iconfont icon-zan"></i> <em>0</em> </span> <span type="reply" class="showpinglun" data-id="1648744"> <i class="iconfont icon-svgmoban53"></i> 讨论(0) </span> <div class="jieda-admin"> </div> </div> <div class="comments-mod " style="display: none; float:none;padding-top:10px;" id="comment_1648744"> <div class="areabox clearfix"> <form class="layui-form" action=""> <div class="layui-form-item"> <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label> <div class="layui-input-block" style="margin-left:90px;"> <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" /> <input type='hidden' value='0' name='replyauthor' /> </div> <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1648744">提交评论 </span></div> </div> </form> </div> <hr> <ul class="my-comments-list nav"> <li class="loading"> <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' /> 加载中... </li> </ul> </div> </li> <li data-id="111"> <a name="item-1111111111"></a> <div class="detail-about detail-about-reply"> <a class="fly-avatar" href="https://www.e-learn.cn/qa/u-45.html"> <img src="https://www.e-learn.cn/qa/data/avatar/000/00/00/small_000000045.jpg" alt=" "> </a> <div class="fly-detail-user"> <a href="https://www.e-learn.cn/qa/u-45.html" class="fly-link"> <cite>耶瑟儿～ </cite> </a> </div> <div class="detail-hits"> <span>2021-01-07 04:38</span> </div> </div> <div class="detail-body jieda-body photos"> <pre><code>function validate() { //Get the user input var hostnames = document.getElementById('yourtextarea').value; //Regex to validate hostname var re = new RegExp(/^([a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,6}$/); //Trim whitespace hostnames = hostnames.trim(); //Explode into an array hostnames = hostnames.split(","); //Loop through array & test each hostname with regex var is_valid = true; for (var i=0; i < hostnames.length; i++){ var hostname = hostnames[i].trim(); if (re.test(hostname)) { is_valid = true; //if valid, continue loop } else { is_valid = false; //if invalid, break loop and return false break; } } //end for loop return is_valid; } //end function validate() </code></pre> <p>Matches every example you indicated except "dom-ain.it, domain.com, domain.eu.org.something" because "something" is not valid.</p> <p>JSFiddle: http://jsfiddle.net/nesutqjf/2/</p> <div class="appendcontent"> </div> </div> <div class="jieda-reply"> <span class="jieda-zan button_agree" type="zan" data-id='1648746'> <i class="iconfont icon-zan"></i> <em>0</em> </span> <span type="reply" class="showpinglun" data-id="1648746"> <i class="iconfont icon-svgmoban53"></i> 讨论(0) </span> <div class="jieda-admin"> </div> </div> <div class="comments-mod " style="display: none; float:none;padding-top:10px;" id="comment_1648746"> <div class="areabox clearfix"> <form class="layui-form" action=""> <div class="layui-form-item"> <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label> <div class="layui-input-block" style="margin-left:90px;"> <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" /> <input type='hidden' value='0' name='replyauthor' /> </div> <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1648746">提交评论 </span></div> </div> </form> </div> <hr> <ul class="my-comments-list nav"> <li class="loading"> <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' /> 加载中... </li> </ul> </div> </li> <li data-id="111"> <a name="item-1111111111"></a> <div class="detail-about detail-about-reply"> <a class="fly-avatar" href="https://www.e-learn.cn/qa/u-26.html"> <img src="https://www.e-learn.cn/qa/data/avatar/000/00/00/small_000000026.jpg" alt=" "> </a> <div class="fly-detail-user"> <a href="https://www.e-learn.cn/qa/u-26.html" class="fly-link"> <cite>星月不相逢 </cite> </a> </div> <div class="detail-hits"> <span>2021-01-07 04:43</span> </div> </div> <div class="detail-body jieda-body photos"> <p>I would not use regexps for this, because you have a <strong>lot</strong> of different rules you want to check. Regexps are good when you only have a couple of rules that are very simple to express but a pain to write out as "parsing code".</p> <p>I'd simply do <code>hostnames.split(',').forEach(validateHostname);</code>, as most of the comments suggest, and inside <code>validateHostname</code> reject any hostname that has spaces in the middle, two adjacent dots, no dots, ends in a dot, has non-ASCII characters, has digits in the last dot-separated token, and so on and so forth.</p> <p>A function like this will be much easier to add new rules to than a regexp would be.</p> <div class="appendcontent"> </div> </div> <div class="jieda-reply"> <span class="jieda-zan button_agree" type="zan" data-id='1648747'> <i class="iconfont icon-zan"></i> <em>0</em> </span> <span type="reply" class="showpinglun" data-id="1648747"> <i class="iconfont icon-svgmoban53"></i> 讨论(0) </span> <div class="jieda-admin"> </div> </div> <div class="comments-mod " style="display: none; float:none;padding-top:10px;" id="comment_1648747"> <div class="areabox clearfix"> <form class="layui-form" action=""> <div class="layui-form-item"> <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label> <div class="layui-input-block" style="margin-left:90px;"> <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" /> <input type='hidden' value='0' name='replyauthor' /> </div> <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1648747">提交评论 </span></div> </div> </form> </div> <hr> <ul class="my-comments-list nav"> <li class="loading"> <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' /> 加载中... </li> </ul> </div> </li> <li data-id="111"> <a name="item-1111111111"></a> <div class="detail-about detail-about-reply"> <a class="fly-avatar" href="https://www.e-learn.cn/qa/u-99.html"> <img src="https://www.e-learn.cn/qa/data/avatar/000/00/00/small_000000099.jpg" alt=" "> </a> <div class="fly-detail-user"> <a href="https://www.e-learn.cn/qa/u-99.html" class="fly-link"> <cite>忘掉有多难 </cite> </a> </div> <div class="detail-hits"> <span>2021-01-07 04:44</span> </div> </div> <div class="detail-body jieda-body photos"> <p>An example with validate.js which has well tested routines for testing a valid FQDN. Alternatively look through the source and grab what you need.</p> <p><div class="snippet" data-lang="js" data-hide="false"> <div class="snippet-code"> <pre class="snippet-code-js lang-js prettyprint-override"><code>function validate (e) { var target = e.target || e; target.value.split(',').some(function (item) { var notValid = !validator.isFQDN(item.trim()); if (notValid) { target.classList.add('bad'); } else { target.classList.remove('bad'); } return notValid; }); } var domains = document.getElementById('domains'); domains.addEventListener('change', validate); validate(domains);</code></pre> <pre class="snippet-code-css lang-css prettyprint-override"><code>#domains { width: 300px; height: 100px; } .bad { background-color: red }</code></pre> <pre class="snippet-code-html lang-html prettyprint-override"><code><script src="http://rawgit.com/chriso/validator.js/master/validator.js"></script> <textarea id="domains">www.example.com, example.com, example.ca, example, example.com example.nl www.example, www.exam ple.com</textarea></code></pre> </div> </div> </p> <div class="appendcontent"> </div> </div> <div class="jieda-reply"> <span class="jieda-zan button_agree" type="zan" data-id='1648749'> <i class="iconfont icon-zan"></i> <em>0</em> </span> <span type="reply" class="showpinglun" data-id="1648749"> <i class="iconfont icon-svgmoban53"></i> 讨论(0) </span> <div class="jieda-admin"> </div> </div> <div class="comments-mod " style="display: none; float:none;padding-top:10px;" id="comment_1648749"> <div class="areabox clearfix"> <form class="layui-form" action=""> <div class="layui-form-item"> <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label> <div class="layui-input-block" style="margin-left:90px;"> <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" /> <input type='hidden' value='0' name='replyauthor' /> </div> <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1648749">提交评论 </span></div> </div> </form> </div> <hr> <ul class="my-comments-list nav"> <li class="loading"> <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' /> 加载中... </li> </ul> </div> </li> <li data-id="111"> <a name="item-1111111111"></a> <div class="detail-about detail-about-reply"> <a class="fly-avatar" href="https://www.e-learn.cn/qa/u-26.html"> <img src="https://www.e-learn.cn/qa/data/avatar/000/00/00/small_000000026.jpg" alt=" "> </a> <div class="fly-detail-user"> <a href="https://www.e-learn.cn/qa/u-26.html" class="fly-link"> <cite>星月不相逢 </cite> </a> </div> <div class="detail-hits"> <span>2021-01-07 04:49</span> </div> </div> <div class="detail-body jieda-body photos"> <p>I have been using this pattern for awhile, and seems to be working for your case, too:</p> <pre><code>/^[a-zA-Z0-9][a-zA-Z0-9\-_]*\.([a-zA-Z0-9]+|[a-zA-Z0-9\-_]+\.[a-zA-Z]+)+$/gi </code></pre> <p>The logic is simple:</p> <ul> <li><code>^[a-zA-Z0-9]</code>: The URL must start with an alphanumeric character</li> <li><code>[a-zA-Z0-9\-_]*</code>: The first alphanumeric character can be followed by zero or more of: an alphanumeric character, an underscore or a dash</li> <li><code>\.</code>: The first piece must be followed by a period.</li> <li>The second piece must follow the same pattern: <ol> <li><code>[a-zA-Z0-9]+</code>: One or more alphanumeric character, OR</li> <li><code>[a-zA-Z0-9\-_]+\.[a-zA-Z0-9]+</code>: One or more alphanumeric character, an underscore or a dash followed by a period and one or more alphanumeric character</li> </ol></li> </ul> <p>You can check this pattern working for most of your URLs in the following code snippet. How I do it is similar to the strategy described by others:</p> <ul> <li>Get the value of the textarea on keyup (or you can bind the submit, blur, keypress, keydown, change and etc)</li> <li>Split the value by the <code>,</code> character</li> <li>Use <code>$.trim()</code> to remove flanking whitespaces</li> <li>Use the RegEx pattern above to evaluate each individual string</li> </ul> <p>Optional, done for visual output:</p> <ul> <li>Generate a list of URLs</li> <li>Indicate if each URL entered is valid or not</li> </ul> <p><div class="snippet" data-lang="js" data-hide="false"> <div class="snippet-code"> <pre class="snippet-code-js lang-js prettyprint-override"><code>$(function() { $('textarea').keyup(function() { var urls = $(this).val().split(','); $('ul').empty(); $.each(urls, function(i,v) { // Trim URL var url = $.trim(v); // RegEx var pat = /^[a-zA-Z0-9][a-zA-Z0-9\-_]*\.([a-zA-Z0-9]+|[a-zA-Z0-9\-_]+\.[a-zA-Z]+)+$/gi, test = pat.test(url); // Append $('ul').append('<li>'+url+' <span>'+test+'</span></li>'); }); }); });</code></pre> <pre class="snippet-code-css lang-css prettyprint-override"><code>textarea { width: 100%; height: 100px; } ul span { background-color: #eee; display: inline-block; margin-left: .25em; padding: 0 .25em; text-transform: uppercase; }</code></pre> <pre class="snippet-code-html lang-html prettyprint-override"><code><script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <textarea placeholder="Paste URLs here"></textarea> <ul></ul></code></pre> </div> </div> </p> <div class="appendcontent"> </div> </div> <div class="jieda-reply"> <span class="jieda-zan button_agree" type="zan" data-id='1648748'> <i class="iconfont icon-zan"></i> <em>0</em> </span> <span type="reply" class="showpinglun" data-id="1648748"> <i class="iconfont icon-svgmoban53"></i> 讨论(0) </span> <div class="jieda-admin"> </div> </div> <div class="comments-mod " style="display: none; float:none;padding-top:10px;" id="comment_1648748"> <div class="areabox clearfix"> <form class="layui-form" action=""> <div class="layui-form-item"> <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label> <div class="layui-input-block" style="margin-left:90px;"> <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" /> <input type='hidden' value='0' name='replyauthor' /> </div> <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1648748">提交评论 </span></div> </div> </form> </div> <hr> <ul class="my-comments-list nav"> <li class="loading"> <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' /> 加载中... </li> </ul> </div> </li> <li data-id="111"> <a name="item-1111111111"></a> <div class="detail-about detail-about-reply"> <a class="fly-avatar" href="https://www.e-learn.cn/qa/u-43.html"> <img src="https://www.e-learn.cn/qa/data/avatar/000/00/00/small_000000043.jpg" alt=" "> </a> <div class="fly-detail-user"> <a href="https://www.e-learn.cn/qa/u-43.html" class="fly-link"> <cite>小蘑菇 </cite> </a> </div> <div class="detail-hits"> <span>2021-01-07 04:58</span> </div> </div> <div class="detail-body jieda-body photos"> <p>While @dandavis's answer/comment is impressive, lets break it down in to steps.</p> <ol> <li>Get the value from the textarea and <code>trim()</code> leading and ending spaces.</li> <li>Replace all white spaces with a single white space using <code>/\s+/g</code>. meaning find every white space occurring one or more times.</li> <li>Split by <code>,<space></code> or <code><space>,<space></code>. Split returns array.</li> <li>Iterate every array element with filter</li> <li>Check if element is a valid domain. If so return it.</li> </ol> <p><div class="snippet" data-lang="js" data-hide="false"> <div class="snippet-code"> <pre class="snippet-code-js lang-js prettyprint-override"><code>var domains = document.querySelector("textarea").value; domains = domains.trim().replace(/\s+/g, " ").split(/\s?,\s/); var domainsTested = domains.filter(function(element){ if (element.match(/^[a-zA-Z0-9][a-zA-Z0-9-_]{0,61}[a-zA-Z0-9]{0,1}\.([a-zA-Z]{1,6}|[a-zA-Z0-9-]{1,30}\.[a-zA-Z]{2,3})$/)) { return element; } }) document.write(domainsTested.join(" | ")); //this is just here to show the results. document.write("<br />Domainstring is ok: " + (domainsTested.length == domains.length)); //If it's valid then this should be equal.</code></pre> <pre class="snippet-code-html lang-html prettyprint-override"><code><textarea style="width: 300px; height: 100px">www.example.com , example.com, example.ca, example, example.com example.nl www.example, www.exam ple.com, sub.sub.sub.domain.tv, do main.it, sub.domain.tv</textarea></code></pre> </div> </div> </p> <div class="appendcontent"> </div> </div> <div class="jieda-reply"> <span class="jieda-zan button_agree" type="zan" data-id='1648745'> <i class="iconfont icon-zan"></i> <em>0</em> </span> <span type="reply" class="showpinglun" data-id="1648745"> <i class="iconfont icon-svgmoban53"></i> 讨论(0) </span> <div class="jieda-admin"> </div> </div> <div class="comments-mod " style="display: none; float:none;padding-top:10px;" id="comment_1648745"> <div class="areabox clearfix"> <form class="layui-form" action=""> <div class="layui-form-item"> <label class="layui-form-label" style="padding-left:0px;width:60px;">发布评论:</label> <div class="layui-input-block" style="margin-left:90px;"> <input type="text" placeholder="不少于5个字" AUTOCOMPLETE="off" class="comment-input layui-input" name="content" /> <input type='hidden' value='0' name='replyauthor' /> </div> <div class="mar-t10"><span class="fr layui-btn layui-btn-sm addhuidapinglun" data-id="1648745">提交评论 </span></div> </div> </form> </div> <hr> <ul class="my-comments-list nav"> <li class="loading"> <img src='https://www.e-learn.cn/qa/static/css/default/loading.gif' align='absmiddle' /> 加载中... </li> </ul> </div> </li> <style> .laypage-main a, .laypage-main span { display: inline-block; } </style> </ul> <div class="layui-form layui-form-pane"> <form id="huidaform" name="answerForm" method="post"> <div class="layui-form-item layui-form-text"> <a name="comment"></a> <div class="layui-input-block"> <script type="text/javascript" src="https://www.e-learn.cn/qa/static/js/neweditor/ueditor.config.js"></script> <script type="text/javascript" src="https://www.e-learn.cn/qa/static/js/neweditor/ueditor.all.js"></script> <script type="text/plain" id="editor" name="content" style="width:100%;height:200px;"></script> <script type="text/javascript"> var isueditor=1; var editor = UE.getEditor('editor',{ //这里可以选择自己需要的工具按钮名称,此处仅选择如下五个 toolbars:[['source','fullscreen', '|', 'undo', 'redo', '|', 'bold', 'italic', 'underline', 'fontborder', 'strikethrough', 'removeformat', 'formatmatch', 'autotypeset', 'blockquote', 'pasteplain', '|', 'forecolor', 'backcolor', 'insertorderedlist', 'insertunorderedlist', 'selectall', 'cleardoc', '|', 'rowspacingtop', 'rowspacingbottom', 'lineheight', '|', 'customstyle', 'paragraph', 'fontfamily', 'fontsize', '|', 'indent', '|', 'justifyleft', 'justifycenter', 'justifyright', 'justifyjustify', '|', 'link', 'unlink', 'anchor', '|', 'simpleupload', 'insertimage', 'scrawl', 'insertvideo', 'attachment', 'map', 'insertcode', '|', 'horizontal', '|', 'preview', 'searchreplace', 'drafts']], initialContent:'', //关闭字数统计 wordCount:false, zIndex:2, //关闭elementPath elementPathEnabled:false, //默认的编辑区域高度 initialFrameHeight:250 //更多其他参数，请参考ueditor.config.js中的配置项 //更多其他参数，请参考ueditor.config.js中的配置项 }); editor.ready(function() { editor.setDisabled(); }); $("#editor").find("*").css("max-width","362px"); </script> </div> </div> <div class="layui-form-item"> <label for="L_vercode" class="layui-form-label">验证码</label> <div class="layui-input-inline"> <input type="text" id="code" name="code" value="" required lay-verify="required" placeholder="图片验证码" autocomplete="off" class="layui-input"> </div> <div class="layui-form-mid"> <span style="color: #c00;"><img class="hand" src="https://www.e-learn.cn/qa/user/code.html" onclick="javascript:updatecode();" id="verifycode"><a class="changecode" href="javascript:updatecode();"> 看不清?</a></span> </div> </div> <div class="layui-form-item"> <input type="hidden" value="682480" id="ans_qid" name="qid"> <input type="hidden" id="tokenkey" name="tokenkey" value=''/> <input type="hidden" value="RegExp to match comma separated hostnames" id="ans_title" name="title"> <div class="layui-btn layui-btn-disabled" id="ajaxsubmitasnwer" >提交回复</div> </div> </form> </div> </div> <input type="hidden" value="682480" id="adopt_qid" name="qid" /> <input type="hidden" id="adopt_answer" value="0" name="aid" /> </div> <div class="layui-col-md4"> <!-- 热门讨论问题 --> <dl class="fly-panel fly-list-one"> <dt class="fly-panel-title">热议问题</dt> <!-- 本周热门讨论问题显示10条-->
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