循环后的逗号

Question

我想给每个用户名加一个逗号，最后一个除外。例如: User1，User2，User3我该怎么做？下面是我的代码：

$user_online_sql = $db->query("SELECT DISTINCT account_id FROM online WHERE account_id != '-1';");
$users = '';
while ($user_online_row = mysql_fetch_array($user_online_sql)) {
$users .= $user->name($user_online_row['account_id']) . ' ';
}

我尝试过内爆函数，但它只输出了一个空结果，下面是内爆函数的代码：

 $user_online_sql = $db->query("SELECT DISTINCT account_id FROM online WHERE account_id != '-1';");
$users = '';
while ($user_online_row = mysql_fetch_array($user_online_sql)) {
$users .= implode(', ',$user->name($user_online_row['account_id'])) . ' ';
} 

Answer 1

你使用implode是对的，但是你做错了。

$users = []; // or array() in PHP 5.3 and older
while($user_online_row = mysql_fetch_assoc($user_online_sql)) {
    $users[] = $user->name($user_online_row['account_id']);
}
$users = implode(", ",$users);
echo $users;

Answer 2

只需在每个用户后面添加一个逗号，并删除尾随的逗号。

$user_online_sql = $db->query("SELECT DISTINCT account_id FROM online WHERE account_id != '-1';");
$users = '';
while ($user_online_row = mysql_fetch_array($user_online_sql)) {
$users .= $user->name($user_online_row['account_id']).',';
}
rtrim ($users, ",");