这个递归的函数为什么不能 return？

This topic created in 3164 days ago, the information mentioned may be changed or developed.

public function getFolder($dir, $num)
{
$targetDir = rtrim($dir, '/');
if (!is_dir($targetDir))
return false;
$result = false;
$folders = scandir($targetDir);
foreach ( $folders as $folder)
{
if($folder == '.' || $folder == '..' || $folder == '__MACOSX' || $folder == '.DS_Store') {
continue;
}
$subDir = $targetDir . DIRECTORY_SEPARATOR . $folder;
if (!is_dir($subDir))
continue;
if ($folder == $num)
{
$result = $targetDir . DIRECTORY_SEPARATOR . $folder;
return $result;
} else {
return $this->getFolder($subDir, $num);
}
}
}

调试了半天，就是不能 return 到数据，return 为空。
如果 else 不 return,可以 echo 出数据，也不能 return 值。

folder

return

targetdir

num

5 replies • 2017-09-22 09:48:18 +08:00

juneszh

Sep 22, 2017

这代码看得累

yejinmo

Sep 22, 2017

public function getFolder($dir, $num)
{
$targetDir = rtrim($dir, '/');
if (!is_dir($targetDir))
return false;
$result = false;
$folders = scandir($targetDir);
foreach ( $folders as $folder)
{
if($folder == '.' || $folder == '..' || $folder == '__MACOSX' || $folder == '.DS_Store')
{
continue;
}
$subDir = $targetDir . DIRECTORY_SEPARATOR . $folder;
if (!is_dir($subDir))
continue;
if ($folder == $num)
{
$result = $targetDir . DIRECTORY_SEPARATOR . $folder;
return $result;
}
else
{
return $this->getFolder($subDir, $num);
}
}
}

yejinmo

Sep 22, 2017

@yejinmo
好吧 V2EX 不支持 tab 缩进。。

sortbylist

Sep 22, 2017

递归要有收敛，if ($folder == $num) 这个条件能成立么？不能成立就无限递归了。

CEBBCAT

Sep 22, 2017 via Android

说句无关的：V2EX 贴代码可以用 gist