php - URL dissector that splits up a query string -

ok reading through piece of source code , not understand purpose of specific area.

class url_processor {     private static $urlpath;     private static $urlbits = array();      /* gets data current url @return void */ public function geturldata() {     $urldata = (isset($_get['page'])) ? $_get['page'] : '' ;     self::$urlpath = $urldata;     if( $urldata == '' )     {         self::$urlbits[] = 'home';         self::$urlpath = 'home';     }     else     {         $data = explode( '/', $urldata );         while ( !empty( $data ) && strlen( reset( $data ) ) === 0 )          {             array_shift( $data );         }         while ( !empty( $data ) && strlen( end( $data ) ) === 0)          {             array_pop($data);         }             self::$urlbits = $this->array_trim( $data );         }     }     private function array_trim( $array )     {         while ( ! empty( $array ) && strlen( reset( $array ) ) === 0)          {             array_shift( $array );         }          while ( !empty( $array ) && strlen( end( $array ) ) === 0)          {             array_pop( $array );         }          return $array;     } } 

so understanding 2 while loops 'array_shift' in geturldata method empty out array according logic second while loop wont able empty out because first while loop did.

then last line of method geturldata

self::$urlbits = $this->array_trim( $data ); 

does same thing how if passed in argument empty already?

very confused!!!

the first while loop removes leading elements in array string length zero, second 1 same trailing elements. reset($array) point first, end($array) last element.

why mushes through second time? don't know.