php 在 while 循环（范围）之外使用变量
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Using a variable outside of the while loop (scope)
提问by Ryan Ward
Small problem regarding scope in PHP, I can't seem to call the variable $report outside of the while loop. I have tried various things, including return. This doesn't work, the only two functions that work here are if I echothe variable $reportinside the loop, or if I printit. Which I do not want to do, although it solves the problem, but I don't want random gibberish on the user's screen.
关于 PHP 范围的小问题，我似乎无法在 while 循环之外调用变量 $report。我尝试了各种方法，包括return. 这是行不通的，这里唯一可以使用的两个函数是如果 I是循环内的echo变量$report，或者如果 I 是print它。我不想这样做，虽然它解决了问题，但我不希望用户屏幕上出现随机乱码。
I have been looking around for the last 15 or so minutes, and I haven't seen any problems quite like this one on here.
在过去的 15 分钟左右，我一直在四处寻找，但我没有看到任何与这里类似的问题。
Any help would be appreciated.
任何帮助，将不胜感激。
<?
require "functions2.php";
require "members.php";
$query = "SELECT MAX(DOCid) as prevDOCid from reports";
$result = mysql_query($query);
while ($row = mysql_fetch_array($result)) {
$prevDOCid = $row[prevDOCid];
$thisDOCid = $prevDOCid+1;
$report = "a"."b".$thisDOCid;
}
echo $report;
?>
回答by Vilius
You could try to define the variable before the loop, e.g.
您可以尝试在循环之前定义变量，例如
$report = "";
while ($row = mysql_fetch_array($result)) {
$report .= "a"."b".$row["prevDOCid"]+1;
}
echo $report;
I hope this helps you!
我希望这可以帮助你！
Edit Use .= not +=
编辑使用 .= 不是 +=
