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This article mainly introduces the method of using JavaScript regular expressions to verify form forms. Friends who need it can refer to it
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<html> <head> <script type="text/javascript"> function show() { //弹出一个提示框 window.alert("hh"); } //将show方法绑定到按钮上 window.onload=function() { //定位到按钮 var buttonElement=document.forms[0].mybtn; //动态绑定show方法 buttonElement.onclick=show; //show如果加()则一加载网页就弹出提示框 } function validateForm() { var loginform=document.forms[1]; var username=trim(loginform.username.value); var password=trim(loginform.password.value); var email=trim(loginform.email.value); // alert("替代前长度:"+username.length); // username=trim(username); // alert("替代后长度:"+username.length); //判断用户名必填: if(username.length==0) { alert("用户必填"); } else if(!/^[a-zA-Z0-9]+$/.test(username)) { alert("用户名必须是英文字母"); } else if(password.length==0) { alert("密码必填"); } else if(!/^[0-9]{6}$/.test(password)) { alert("密码必须为6位数字"); } else if(email.length==0) { alert("邮箱必填"); } else if(!/^\w+@\w+(\.\w+)+$/.test(email)) { alert("邮箱格式不正确"); } return false; } //自定义一个去空格的参数 function trim(s) { //s.REPLACE(正则表达式,替换的字符) s=s.replace(/^\s*$/,""); return s; } </script> <style type="text/css"> .myclass{ position: absolute; left: 400px; top: 150px; } </style> </head> <body> <p class="myclass"> <form action="#" name="myform" method="post"> <input type="button" value="单机" name="mybtn"/> </form> </p> <!--登录页面的表单--> <form action="#" name="loginform" method="post" onsubmit="return validateForm()"> <table border="1" align="center"> <caption>基于js的验证</caption> <tr> <th>用户名:</th> <td><input type="text" name="username"/></td> </tr> <tr> <th>密码:</th> <td><input type="password" name="password"/></td> </tr> <tr> <th>邮箱:</th> <td><input type="text" name="email"/></td> </tr> <tr> <td align="center" colspan="2"> <input type="submit" value="提交" /> </td> </tr> </table> </form> </body> </html>
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