Question

这是我第一次使用PHP而且我不知道这段代码有什么问题。

第20行是if语句：if (isset($_COOKIE['hash'])) {

<?php
if (!isset($_GET['page'])) {
    header('Location: /main');
    exit();
}

ini_set('display_errors','Off');
try {
    $database_host = "localhost";
    $database_name = "NAME";
    $database_user = "USER"; //name for phpMyAdmin in bplaced
    $database_pass = "*******"; //password in phpMyAdmin in bplaced
    global $db;
    $db = mysqli_connect($database_host, $database_user, $database_pass, $database_name) or 
        die('Connect Error (' . mysqli_connect_errno() . ') ' . mysqli_connect_error());
    mysqli_set_charset($db, "utf8"); 
}

if (isset($_COOKIE['hash'])) {
    $sql = $db->query("SELECT * FROM `users` WHERE `hash` = " . $db->quote($_COOKIE['hash']));
    if ($sql->rowCount() != 0) {
        $row = $sql->fetch();
        $user = $row;
    }
}

Answer 1

错误表示您的代码缺少catch(){}块。

try-catch的语法是：

try
{
    //Do something here which might cause an exception
}
catch(Exception $e)
{
   //You are here means that the exception occurred now do something else here.
}

你也可以有一个finally子句，如果总是执行是否发生异常，或者不是下面的语法：

try
{ 
  print "this is our try block\n";
  throw new Exception();
}
catch (Exception $e)
{
  print "something went wrong\n";
}
finally
{
  print "This part is always executed\n";
}

Answer 2

关闭try块后需要输入一个catch语句，如下所示：

<?php
if (!isset($_GET['page'])) {
    header('Location: /main');
    exit();
}

ini_set('display_errors', 'Off');
try {
    $database_host = "localhost";
    $database_name = "NAME";
    $database_user = "USER"; //name for phpMyAdmin in bplaced
    $database_pass = "*******"; //password in phpMyAdmin in bplaced
    global $db;
    $db = mysqli_connect($database_host, $database_user, $database_pass, $database_name) or die('Connect Error (' . mysqli_connect_errno() . ') ' . mysqli_connect_error());
    mysqli_set_charset($db, "utf8");
}
catch (Exception $e) {
    // do something
}

if (isset($_COOKIE['hash'])) {
    $sql = $db->query("SELECT * FROM `users` WHERE `hash` = " . $db->quote($_COOKIE['hash']));
    if ($sql->rowCount() != 0) {
        $row  = $sql->fetch();
        $user = $row;
    }
}

Answer 3

在try块之后你缺少catch块。每次尝试必须在PHP中至少有一个相应的catch或finally块。参考：http://php.net/manual/en/language.exceptions.php

致命错误：无法使用try without catch或最终在/users/xxx/www/index.php第20行

3 个答案: