在 while 循环(范围)之外使用变量 [英] Using a variable outside of the while loop (scope)

问题描述

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，如果我 echo 循环内的变量 $report，或者如果我 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.

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 echo the variable $report inside the loop, or if I print it. Which I do not want to do, although it solves the problem, but I don't want random gibberish on the user's screen.

过去 15 分钟左右我一直在环顾四周，我没有看到任何与这里类似的问题.

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.

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;
?>

推荐答案

您可以尝试在循环之前定义变量，例如

You could try to define the variable before the loop, e.g.

$report = "";
while ($row = mysql_fetch_array($result)) {
    $report .= "a"."b".$row["prevDOCid"]+1;
}
echo $report;

希望对你有帮助！

编辑使用 .= not +=

Edit Use .= not +=

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