6 Methods for PHP to obtain the file extension

Yesterday, I talked to a friend in a PHP chat group (276167802, verification: csl, if you are interested, you can join in and discuss it) and mentioned six methods for PHP to get the file extension, now let's share with you: 1. string search and truncation method $ extension = subst yesterday, a friend in a PHP chat group (276167802, verification: csl, if you are interested, you can join the discussion .) PHPYou can use the following six methods to obtain the file extension:

1. string search and truncation methods

$ Extension = substr (strrchr ($ file, '.'), 1 );

2. Method 2 for string search and truncation

$ Extension = substr ($ file, strrpos ($ file, '.') + 1 );

3. array partitioning

$ Extension = end (explode ('.', $ file ));

4. direct parsing using pathinfo

$ Info = pathinfo ($ file); $ extension = $ info ['extension'];

5. use the second parameter of pathinfo

$ Extension = pathinfo ($ file, PATHINFO_EXTENSION );

6. use the finfo_file function

$ Finfo = finfo_open (FILEINFO_MIME_TYPE); $ extension = finfo_file ($ finfo, $ file); echo $ extension; finfo_close ($ finfo );