本文实例讲述了php校验表单检测字段是否为空的方法。分享给大家供大家参考。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>
php后端代码，保存为： errorcheck.php
<html>
<body>
<?php
$errorcount=0;
if (!trim($_post['nickname'])) {
echo "<br /><b>nickname</b> is required.";
$errorcount++;
}
if (!trim($_post['title'])) {
echo "<br /><b>title</b> is required.";
$errorcount++;
}
if ($errors > 0)
echo "<br /><br />please use your browser's back button " .
"to return to the form, and correct error(s)";
?>
</body>
</html>
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. " ″ (ascii 0 (0×00)), the nul-byte. "x0b" (ascii 11 (0x0b)), a vertical tab.
希望本文所述对大家的php程序设计有所帮助。
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