我收到错误调用未定义的函数

Question

嗨，我是 php 的新手，在测试一些代码时我遇到了未定义函数的错误

<!DOCTYPE html>
<html>
<head>
</head>
<body>

<form method="POST" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
 <input type="text" placeholder="type your full name" name="fullname">
 <input type="submit" name="submit" value="submit">
</form>

<?php
 $getName = "" ;
 if ($_SERVER["REQUEST_METHOD"] == "POST") {
  $getName = "hello ".test_input($_POST['fullname']);  //Fatal error: Call to undefined function test_input() in C:\xampp\htdocs\ctPHP.php on line 15
   
  function test_input($data) {
    $data = trim($data);
    $data = stripslashes($data);
    $data = htmlspecialchars($data);
    return $data;
  }
 } 
 echo $getName;
?>

</body>
</html>

我想知道如何解决这个问题，我想在文本字段中回显输入的名称，如何解决这个问题，谢谢

Answer 1

只需要在函数创建后回显即可。

首先创建函数 test_input() 然后在 declaration/defination 之后使用它。

<!DOCTYPE html>
<html>
<head>
</head>
<body>

<form method="POST" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
    <input type="text" placeholder="type your full name" name="fullname">
    <input type="submit" name="submit" value="submit">
</form>

<?php
    $getName = "" ;
    if ($_SERVER["REQUEST_METHOD"] == "POST") {
         function test_input($data) {
          $data = trim($data);
          $data = stripslashes($data);
          $data = htmlspecialchars($data);
          return $data;
     }
        $getName = "hello ".test_input($_POST['fullname']);  //Fatal error: Call to undefined function test_input() in C:\xampp\htdocs\ctPHP.php on line 15


    } 
    echo $getName;
?>

</body>
</html>

我收到错误调用未定义的函数

I'm getting error Call to undefined function

php

undefined