javascript - character limit</h1> <div id="body"><p>What is a <em>cross-browser</em> way to set the maximum number of characters in a textarea, using plain Javascript? <a href="http://www.w3schools.com/tags/att_textarea_max</a></h1> <div class="ml12 aside-cta flex--item print:d-none sm:ml0 sm:mb12 sm:order-first sm:as-end"> <a href="https://stackoverflow.com/questions/ask" target="_blank" class="ws-nowrap s-btn s-btnprimary">質問する</a></div> </div> <div class="d-flex fw-wrap pb8 mb16 bb bc-black-075"> <div class="flex--item ws-nowrap mr16 mb8"> <span class="fc-light mr2"></span> </div> <div class="flex--item ws-nowrap mr16 mb8" title="2022-04-17 15:46:40Z"> <span class="fc-light mr2">質問する</span> <time itemprop="dateCreated" datetime="2013-08-24T18:03:51.233">2013-08-24T18:03:51.233</time> </div> <div class="flex--item ws-nowrap mb8" title="Viewed 6 times"> <span class="fc-light mr2"></span> 3226 次 </div> </div> <div id="mainbar" role="main" aria-label="question and answers"> <div class="question" data-questionid="4" data-position-on-page="0" data-score="763" id="question"> <div class="post-layout"> <div class="votecell post-layout--left"> <div class="js-voting-container d-flex jc-center fd-column ai-stretch gs4 fc-black-200" data-post-id="4"> <button class="js-vote-up-btn flex--item s-btn s-btnunset c-pointer " data-controller="s-tooltip" data-s-tooltip-placement="right" aria-pressed="false" aria-label="Up vote" data-selected-classes="fc-theme-primary" data-unselected-classes="" aria-describedby="--stacks-s-tooltip-peeufs8c"> <svg aria-hidden="true" class="svg-icon iconArrowUpLg" width="36" height="36" viewBox="0 0 36 36"><path d="M2 25h32L18 9 2 25Z"></path></svg> </button> <div id="--stacks-s-tooltip-peeufs8c" class="s-popover s-popovertooltip pe-none" aria-hidden="true" role="tooltip">This question shows research effort; it is useful and clear<div class="s-popover--arrow"></div></div> <div class="js-vote-count flex--item d-flex fd-column ai-center 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mx-auto" data-shortcut="T" data-ks-title="timeline" data-controller="s-tooltip" data-s-tooltip-placement="right" aria-label="Timeline" aria-describedby="--stacks-s-tooltip-abwmy15k"><svg aria-hidden="true" class="mln2 mr0 svg-icon iconHistory" width="19" height="18" viewBox="0 0 19 18"><path d="M3 9a8 8 0 1 1 3.73 6.77L8.2 14.3A6 6 0 1 0 5 9l3.01-.01-4 4-4-4h3L3 9Zm7-4h1.01L11 9.36l3.22 2.1-.6.93L10 10V5Z"></path></svg></a><div id="--stacks-s-tooltip-abwmy15k" class="s-popover s-popovertooltip pe-none" aria-hidden="true" role="tooltip">Show activity on this post.<div class="s-popover--arrow"></div></div> </div> </div> <div class="postcell post-layout--right"> <div class="s-prose js-post-body" itemprop="text"> </div> <div class="mt24 mb12"> <div class="post-taglist d-flex gs4 gsy fd-column"> <div class="d-flex ps-relative fw-wrap"> <a href="/tags/javascript" class="post-tag js-gps-track" title="show questions tagged 'javascript'" rel="tag">javascript</a><a href="/tags/html" class="post-tag js-gps-track" title="show questions tagged 'html'" rel="tag">html</a><a href="/tags/textarea" class="post-tag js-gps-track" title="show questions tagged 'textarea'" rel="tag">textarea</a><a href="/tags/maxlength" class="post-tag js-gps-track" title="show questions tagged 'maxlength'" rel="tag">maxlength</a> </div> </div> </div> </div> <span class="d-none" itemprop="commentCount">4</span> </div> </div> <div class="js-zone-container zone-container-responsive"> <div id="dfp-isb" class="everyonelovesstackoverflow everyonelovesinline-sidebar mx-auto" style="min-height: auto; height: auto; display: none;"></div> <div class="js-report-ad-button-container mx-auto" style="width: 300px"></div> </div> <div id="answers"> <a name="tab-top"></a> <div id="answers-header"> <div class="answers-subheader d-flex ai-center mb8"> <div class="flex--item fl1"> <h2 class="mb0" data-answercount=""> 1 に答える <span style="display:none;" itemprop="answerCount">1</span> </h2> </div> </div> </div> <a name="7"></a> <div id="answer-7" class="answer js-answer accepted-answer" data-answerid="7" data-parentid="4" data-score="506" data-position-on-page="1" data-highest-scored="1" data-question-has-accepted-highest-score="1" itemprop="suggestedAnswer" itemscope="" itemtype="https://schema.org/Answer"> <div class="post-layout"> <div class="votecell post-layout--left"> <div class="js-voting-container d-flex jc-center fd-column ai-stretch gs4 fc-black-200" data-post-id="7"> <button class="js-vote-up-btn flex--item s-btn s-btnunset c-pointer " data-controller="s-tooltip" data-s-tooltip-placement="right" aria-pressed="false" aria-label="Up vote" data-selected-classes="fc-theme-primary" data-unselected-classes="" aria-describedby="--stacks-s-tooltip-dgvag2l3"> <svg aria-hidden="true" class="svg-icon iconArrowUpLg" width="36" height="36" viewBox="0 0 36 36"><path d="M2 25h32L18 9 2 25Z"></path></svg> </button><div id="--stacks-s-tooltip-dgvag2l3" class="s-popover s-popovertooltip pe-none" aria-hidden="true" role="tooltip">This answer is useful<div class="s-popover--arrow"></div></div> <div class="js-vote-count flex--item d-flex fd-column ai-center fc-black-500 fs-title" itemprop="upvoteCount" data-value="3"> 3 </div> <button class="js-vote-down-btn flex--item s-btn s-btnunset c-pointer " data-controller="s-tooltip" data-s-tooltip-placement="right" aria-pressed="false" aria-label="Down vote" data-selected-classes="fc-theme-primary" data-unselected-classes="" aria-describedby="--stacks-s-tooltip-gn8ppsfv"> <svg aria-hidden="true" class="svg-icon iconArrowDownLg" width="36" height="36" viewBox="0 0 36 36"><path d="M2 11h32L18 27 2 11Z"></path></svg> </button> </div> </div> <div class="answercell post-layout--right"> <div class="s-prose js-post-body" itemprop="text"> <p><em>値</em>を切り捨てるか、条件の下で<em>イベント</em>を防止する<em>関数</em>を生成し、関心のあるすべてのイベントの複数の異なるリスナーとしてそれらを追加します。<em></em><em></em></p> <pre><code>function snip(len) { return function (e) {e.target.value = e.target.value.slice(0, len);}; } function prevent(len) { return function () { if (e.target.value.length >= len) { e.preventDefault(); return false; } }; } var len = 5; // choose your length however you want var textarea = document.getElementById('texta'), // get the node trunc = snip(len), prev1 = prevent(len), prev2 = prevent(len - 1); textarea.addEventListener('change' , trunc, true); textarea.addEventListener('input' , trunc, true); textarea.addEventListener('keydown' , prev2, true); textarea.addEventListener('keypress', prev2, true); textarea.addEventListener('keyup' , prev1, true); textarea.addEventListener('paste' , trunc, true); </code></pre> <p>IE では、イベントを別の方法で添付する必要がある場合があります。</p> <p><a href="http://jsfiddle.net/fad2A/" rel="nofollow"><strong>デモ</strong></a></p> </div> <div class="mt24"> <div class="user-action-time" style="color:#999;text-align:right;">于 2013-08-24T18:15:36.043 に答える</div> </div> </div> </div> </div></div> </div> <div id="sidebar" class="show-votes" 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