Common ways to get file extensions in PHP

This article mainly introduces the common methods of obtaining file extensions in PHP. It summarizes and analyzes five common operating techniques of obtaining file extensions in PHP in the form of examples. Friends in need can refer to the examples in this article.

Summarizes the common methods of obtaining file extensions in PHP. Share it with everyone for your reference, the details are as follows:

This is a written test question I encountered when applying for an internship:

Use more than five methods to obtain the extension of a file.

Requirements: dir/upload.image.jpg, find .jpg or jpg,

Must use PHP's own processing function for processing, the method cannot be obviously repeated, and can be encapsulated into a function, For example, get_ext1($file_name), get_ext2($file_name)

The following are five methods I summarized by referring to online information. They are all relatively simple and do not say much. Say, go directly to the code:

Method 1:

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

Method 2:

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

Method 3:

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

Method 4:

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

Method 5:

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

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7 ways to get file extensions in PHP

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