Question

我需要som帮助使用提交按钮向会话变量添加值。如果我将变量定义为0则不会计数，如果我不这样做，则说：

“注意：未定义的索引：paperbagCount in   第52行/home/saxon/students/20151/chwi15/www/affar3/test.php“

“注意：未定义的索引：plasticbagCount in   第59行/home/saxon/students/20151/chwi15/www/affar3/test.php“

<?php 
if(!session_status() === PHP_SESSION_ACTIVE ) {
session_start();
$_SESSION["paperbagCount"] = 0;
$_SESSION["plasticbagCount"] = 0; 
} 
session_start();
error_reporting(-1);

?>

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="utf-8">
   <title>Startsida</title>   
</head>

<body>

<?php 
if(isset($_POST['addPaper'])) {
  $_SESSION["paperbagCount"]+=1;
}

if(isset($_POST['deletePaper'])) {
    if ($_SESSION["paperbagCount"] == 0) {
        $_SESSION["paperbagCount"] == 0; 
    }else{      
    $_SESSION["paperbagCount"]-=1;
    }
}

if(isset($_POST['addPlastic'])) {
  $_SESSION["plasticbagCount"]+=1;
}

if(isset($_POST['deletePlastic'])) {
    if ($_SESSION["plasticbagCount"] == 0) {
        $_SESSION["plasticbagCount"] == 0; 
    }else{      
    $_SESSION["plasticbagCount"]-=1;
    }
}

?>  

<form method="post">
<p><label>Paperbagcount</label><br>
<input type="submit" name="addPaper" value="+">
<?php echo $_SESSION["paperbagCount"] . "\n"; ?>
<input type="submit" name="deletePaper" value="-">
</form>

<form method="post">
<p><label>Plasticbagcount</label><br>
<input type="submit" name="addPlastic" value="+">
<?php echo $_SESSION["plasticbagCount"] . "\n"; ?>
<input type="submit" name="deletePlastic" value="-">
</form>

</body>
</html>

Answer 1

用这个替换你的PHP代码

<?php 
@session_start(); // @ to avoid warning
if (!isset($_SESSION["paperbagCount"])) {
    $_SESSION["paperbagCount"] = 0;
}
if (!isset($_SESSION["plasticbagCount"])) {
    $_SESSION["plasticbagCount"] = 0;
}
?>

Answer 2

session_start()根据通过GET或POST请求传递的会话标识符创建会话或恢复当前会话，或通过cookie传递。

因此请从代码中删除第二行session_start()。

PHP：使用会话变量的计数器

2 个答案: