PHP uses validation form to detect whether fields are empty-PHP Tutorial-php.cn

PHP uses validation form to detect whether fields are empty

墨辰丷

Release： 2023-03-31 18:16:01

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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。

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

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php后端代码，保存为： ErrorCheck.php

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

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trim()函数可以去除字符串中的前后空字符

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