★JS判断输入框不能为空代码(附我的磨专用版)★

请勿抄袭本页面

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代码说明

我们最基本的判断输入框不能为空就是 varxx !=\"\"这是最简单的了，如果我们要注入这种很简单直接按空格键等等都可以让你验证无效了，下面介绍一个不错的判断输入框不能为空程序。转自壹聚教程

我的磨专用版需填写留言板ID(查看留言板页面地址的最后几个数字)

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html代码

<script language="JavaScript"> <!-- function checkChinese() { var isnumandchar; var StrForCheck=form_key.keywords.value; var c; c = StrForCheck.charAt(0); while((c ==" "||c =="　") && StrForCheck.length > 0) { StrForCheck = StrForCheck.slice(1); c = StrForCheck.charAt(0); } c = StrForCheck.charAt(StrForCheck.length -1); while((c ==" "||c =="　") && StrForCheck.length > 0) { StrForCheck = StrForCheck.substring(0,StrForCheck.length-1); c = StrForCheck.charAt(StrForCheck.length -1); } form_key.keywords.value = StrForCheck;//如果没有值，继续 if (StrForCheck.length==0 || StrForCheck.length<2) { if (StrForCheck.length==0) {alert("注意：输入内容不能为空 !");return false;} } else {return true;} } //--> </script> <form method="POST" name="form_key" onsubmit="return checkChinese();"> <input type="text" name="keywords"> <input type="submit" value="发 送"> </form>

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代码演示

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html代码(我的磨专用)

<script language="JavaScript"> <!-- function checkChinese1() { var isnumandchar; var StrForCheck=form_talk.content.value; var c; c = StrForCheck.charAt(0); while((c ==" "||c =="　") && StrForCheck.length > 0) { StrForCheck = StrForCheck.slice(1); c = StrForCheck.charAt(0); } c = StrForCheck.charAt(StrForCheck.length -1); while((c ==" "||c =="　") && StrForCheck.length > 0) { StrForCheck = StrForCheck.substring(0,StrForCheck.length-1); c = StrForCheck.charAt(StrForCheck.length -1); } form_talk.content.value = StrForCheck;//如果没有值，继续 if (StrForCheck.length==0 || StrForCheck.length<2) { if (StrForCheck.length==0) {alert("注意：输入内容不能为空 !");return false;} } else {return true;} } //--> </script> <form action="http://s.wodemo.com/" method="post" name="form_talk" onsubmit="return checkChinese1();"><input type="hidden" name="act" value="file_talk" /><input type="hidden" name="fid" value="留言板ID" /><input type="text" name="content" value=""/><input type="submit" value="留言" /></form>

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代码演示(我的磨专用)

输入个空格或留空，再点按钮看看

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[代码仅供参考，转载请注明出处]

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