PHP-php中foreach和for到底有没有区别，尤其是在处理多线程（本例是对IOS进行推送）方面？

Question

遇到一个困难，解决了好长时间，最后发现是用for 不好使，用foreach好使。
这段代码是针对php对IOS推送的代码。
用foreach那里，如果改成for i=0 i<长度,那样，print_r("the ".$i." item :".$deviceToken);这里就只能打印出数组第一条内容（我确定如果抛开这个代码单独打印数组是可以打印出来所有内容的），如果用foreach则都能打印。。这里用for为什么不行呢？

<?php
 // 循环有问题
require_once "/home/bae/app/include/db.php";
 
$db_obj = new DB();
$sql = "select appleID from appleDevice ";
$result = $db_obj->db_array($sql);

print_r("the array is:".$result);

var_dump($result);
 
$countArray = count($result); 
 
print_r("number:".$countArray);

    $passphrase = 'zhaojian';
    $message = 'My first push notification!';
     
    $ctx = stream_context_create();
    stream_context_set_option($ctx, 'ssl', 'local_cert', 'ck.pem');
    stream_context_set_option($ctx, 'ssl', 'passphrase', $passphrase);
     
    // Open a connection to the APNS server
    $fp = stream_socket_client(
        'ssl://gateway.sandbox.push.apple.com:2195', $err,
        $errstr, 60, STREAM_CLIENT_CONNECT|STREAM_CLIENT_PERSISTENT, $ctx);
     
    if (!$fp)
        exit("Failed to connect: $err $errstr" . PHP_EOL);
     
    echo 'Connected to APNS' . PHP_EOL;

    // Create the payload body
    $body['aps'] = array(
        'alert' => $message,
        'sound' => 'default'
        );
     
    // Encode the payload as JSON
    $payload = json_encode($body);
 
    //$result = array("2d4401e324e7bd0ce574508b0849c7584b965df4ab183c82b3da65855835ec27","e20f2879b0ff6b7c6554b44f339c9e4bade2ee4a5a3a6d5de77bda074269221f");
    
    foreach ($result as $device) {
    $deviceToken = $device['appleID'];

    print_r("the ".$i." item :".$deviceToken);

    $msg = chr(0) . pack('n', 32) . pack('H*', $deviceToken) . pack('n', strlen($payload)) . $payload;
    $result = fwrite($fp, $msg, strlen($msg));

    if (!$result)
        echo 'Message not delivered' . PHP_EOL;
    else
        echo 'Message successfully delivered' . PHP_EOL;
} 
     
     
    fclose($fp);   

?>

Answer 1

问题已经解决，result重名问题，还有就是foreach循环的是数组的拷贝，所以才没产生问题