$files="./Upload/images/2018-02-04/5a76dda34c018.jpg|./Upload/images/2018-02-04/5a76dda34c5ba.jpg|";
$files=rtrim($files, "|");
$files=explode("|",$files);
foreach ($files as $key => $value) {
$files_root=$files[$key];
$files_root.=$files_root;
}
怎样才能得到 $files_root="./Upload/images/2018-02-04/5a76dda34c018.jpg,./Upload/images/2018-02-04/5a76dda34c5ba.jpg,";