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PHP uses validation form to detect whether fields are empty

Jun 12, 2018 pm 01:38 PM

php Is empty Field method check Detection form

这篇文章主要介绍了php校验表单检测字段是否为空的方法,涉及php验证表单的技巧,非常具有实用价值,需要的朋友可以参考下

本文实例讲述了php校验表单检测字段是否为空的方法。

具体如下：

php校验表单，检测字段是否为空，当表单中有未填写的字段，则会显示错误信息。

&lt;html&gt;
&lt;body&gt;
&lt;form METHOD=&quot;POST&quot; ACTION=&quot;ErrorCheck.php&quot;&gt;
&lt;h1&gt;Contact Information&lt;/h1&gt;
&lt;label&gt;Nickname:&lt;/label&gt;
&lt;input TYPE=&quot;TEXT&quot; NAME=&quot;nickname&quot;&gt;
&lt;label&gt;Title:&lt;/label&gt;
&lt;input TYPE=&quot;TEXT&quot; NAME=&quot;title&quot;&gt;
&lt;br /&gt;
&lt;input TYPE=&quot;SUBMIT&quot; VALUE=&quot;Submit&quot;&gt;
&lt;br /&gt;
&lt;input TYPE=&quot;RESET&quot; VALUE=&quot;Clear the Form&quot;&gt;
&lt;/form&gt;
&lt;/body&gt;
&lt;/html&gt;

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php后端代码，保存为： ErrorCheck.php

&lt;html&gt;
&lt;body&gt;
&lt;?php
 $errorcount=0;
 if (!trim($_POST[&#39;nickname&#39;])) {
   echo &quot;&lt;br /&gt;&lt;b&gt;Nickname&lt;/b&gt; is required.&quot;;
   $errorcount++;
 }
 if (!trim($_POST[&#39;title&#39;])) {
   echo &quot;&lt;br /&gt;&lt;b&gt;Title&lt;/b&gt; is required.&quot;;
   $errorcount++;
 }
 if ($errors &gt; 0)
   echo &quot;&lt;br /&gt;&lt;br /&gt;Please use your browser&#39;s back button &quot; .
    &quot;to return to the form, and correct error(s)&quot;;
 ?&gt;
&lt;/body&gt;
&lt;/html&gt;

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trim()函数可以去除字符串中的前后空字符

&quot; &quot; (ASCII 32 (0×20)), an ordinary space.
&quot;\t&quot; (ASCII 9 (0×09)), a tab.
&quot;\n&quot; (ASCII 10 (0x0A)), a new line (line feed).
&quot;\r&quot; (ASCII 13 (0x0D)), a carriage return.
&quot;\0″ (ASCII 0 (0×00)), the NUL-byte.
&quot;\x0B&quot; (ASCII 11 (0x0B)), a vertical tab.

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总结：以上就是本篇文的全部内容，希望能对大家的学习有所帮助。