PHP实现获取文件后缀名的几种常用方法

方法1：

function get_file_type($filename){
  $type = substr($filename, strrpos($filename, ".")+1);
  return $type;
}

方法2：

function get_file_type($filename)
{
   $type = pathinfo($filename);
   $type = strtolower($type["extension"]);
   return $type;
}

方法3：

function get_file_type($filename)
{  
   $type =explode("." , $filename);
   $count=count($type)-1;
   return $type[$count];
}

方法4：

function getExt1($filename)
{
   $arr = explode('.',$filename);
   return array_pop($arr);;
}

方法5：

function getExt2($filename)
{
   $ext = strrchr($filename,'.');
   return $ext;
}

方法6：

function getExt3($filename)
{
   $pos = strrpos($filename, '.');
   $ext = substr($filename, $pos);
   return $ext;
}

方法7：

function getExt4($filename)
{
   $arr = pathinfo($filename);
   $ext = $arr['extension'];
   return $ext;
}

方法8：

function getExt5($filename)
{
   $str = strrev($filename);
   return strrev(strchr($str,'.',true));
}