php校验表单检测字段是否为空的方法

5年以前 | 阅读数：1039 次 | 编程语言：PHP

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.
    "\0″ (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。