按钮点击计数器[PHP]

问题描述

我试图创建一个变量来存储点击的按钮数。不幸的是我得到这个错误：

 未定义变量：counter 
  

这是我的代码：

  if（$ _SERVER [REQUEST_METHOD] ==POST）{
 $ counter = isset（$ _ POST ['counter']）？ $ _POST ['counter']：0; 
 if（isset（$ _ POST [button]））{
 $ counter ++; 
 echo $ counter; 
 
 
  

它是一种形式：

 < form action =<？php echo htmlspecialchars（$ _ SERVER [PHP_SELF]）;？> method = post> 
< input type =submitname =buttonvalue =Submit> 
< input type =hiddenname =countervalue =<？php print $ counter;？>; /> 
< / form> 
  

有人知道我做错了什么吗？

解决方案

代码中没有错误。它在我的最后工作。您需要检查两点：

1. PHP代码应该在HTML上面，HTML代码会在PHP代码之后出现。因此， $ counter 变量将被初始化。

2. PHP和HTML代码应该位于同一页面上。
>因此，行 $ counter = isset（$ _ POST ['counter']）？ $ _POST ['counter']：0; 不应该在if块中。可以肯定的是，**将此行作为PHP文件的第一行。然后只有 $ counter 变量可用于整个页面。



I tried to create a variable to store a count of button clicked. Unfortunetlly i get this error:

 Undefined variable: counter

It's my code:

if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $counter = isset($_POST['counter']) ? $_POST['counter'] : 0;
    if(isset($_POST["button"])){
        $counter++;
        echo $counter;
    }
}

And it's a form:

<form action = "<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>" method = post>
    <input type = "submit" name = "button" value = "Submit" >
    <input type = "hidden" name = "counter" value = "<?php print $counter; ?>"; />
</form>

Anybody know what i'm doing wrong?

解决方案

There is no error in your code. Its working at my end. You need to check two points:

1. PHP code should be above on HTML, HTML code will come after PHP code. So that $counter variable will be initialized.

2. PHP and HTML code should be on same page.

---

As OP edited the question: So, the line $counter = isset($_POST['counter']) ? $_POST['counter'] : 0; should not be in if-block. To be sure, ** Make this line as a first line of PHP file. Then only $counter variable will be available for whole page.

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