<!doctype html> <html> <head> <meta charset="utf-8"> <title>jquery自动监测输入字数，自动截取，输入框</title> <script src="https://libs.baidu.com/jquery/1.9.1/jquery.min.js"></script> </head> <body> <div class="box"> <textarea style="width: 500px;height: 250px" id="textarea"></textarea> </div> <div> <div id="nobr">0</div>/300 </div> </body> <script> $(document).on("keyup", "textarea", function() { var data = $("#textarea").val().trim().replace(/\s+/g, ""); var count = data.length; if (count > 300) { var new_data = data.substring(0, 300); $(".box").html(new_data); $("#nobr").text(300); } else { $("#nobr").text(count); } }) </script> </html>
