Php reload array operator _ PHP Tutorial

Php overload array operator. Many interfaces are provided in php to implement some very specific functions. for example, if you want to use an object as an array, you only need to implement the ArrayAccess interface, when you want foreach to provide many interfaces in php to implement some very specific functions, for example, if you want to use an object as an array, you only need to implement the ArrayAccess interface, to use an object in foreach, you only need to implement the Iterator interface. The following is an example.

Class BtstoreRoot {/*** root node * @ var BtstoreElement */static $ root;} class BtstoreElement implements ArrayAccess, iterator {/*** the directory currently represented * @ var string */private $ dataDir;/*** the data currently represented * @ var array */private $ arrData; /*** constructor ** @ param string $ dataDir * @ param array $ arrData */function _ construct ($ dataDir, $ arrData) {$ this-> dataDir = ''; $ this-> arrData = array (); if (! Empty ($ dataDir) & is_dir ($ dataDir) {$ this-> dataDir = $ dataDir;} if (! Empty ($ arrData) {$ this-> arrData = $ arrData;} function _ get ($ key) {if (isset ($ this-> arrData [$ key]) {$ data = $ this-> arrData [$ key]; if (is_array ($ data )&&! Is_object ($ data) {$ data = new BtstoreElement ('', $ data);} return $ data;} if (! Empty ($ this-> dataDir) {$ path = $ this-> dataDir. '/'. $ key; if (is_dir ($ path) {$ data = new BtstoreElement ($ path, null); $ this-> arrData [$ key] = $ data; return $ data;} if (is_file ($ path) {$ content = file_get_contents ($ path); $ arrData = unserialize ($ content ); $ data = new BtstoreElement ('', $ arrData); $ this-> arrData [$ key] = $ data; return $ data ;}} trigger_error (" undefined index: $ key ");} Function _ isset ($ key) {if (isset ($ this-> arrData [$ key]) {return true;} if (file_exists ($ this-> dataDir. '/'. $ key) {return true;} return false;} function toArray () {return $ this-> arrData;}/* (non-PHPdoc) * @ see ArrayAccess :: offsetExists () */public function offsetExists ($ offset) {return $ this->__ isset ($ offset) ;}/ * (non-PHPdoc) * @ see ArrayAccess :: offsetGet () */public function offsetGet ($ offset) {Return $ this->__ get ($ offset);}/* (non-PHPdoc) * @ see ArrayAccess: offsetSet () */public function offsetSet ($ offset, $ value) {trigger_error ('offsetset not implemented by btstoreelement');}/* (non-PHPdoc) * @ see ArrayAccess: offsetUnset () */public function offsetUnset ($ offset) {trigger_error ('offsetunset not implemented by BtstoreElement ');}/* (non-PHPdoc) * @ see Iterator: current () */public Function current () {return current ($ this-> arrData);}/* (non-PHPdoc) * @ see Iterator: next () */public function next () {return next ($ this-> arrData);}/* (non-PHPdoc) * @ see Iterator: key () */public function key () {return key ($ this-> arrData);}/* (non-PHPdoc) * @ see Iterator: valid () */public function valid () {$ data = current ($ this-> arrData); return! Empty ($ data);}/* (non-PHPdoc) * @ see Iterator: rewind () */public function rewind () {reset ($ this-> arrData) ;}}/*** get a BtstoreElement object * @ return BtstoreElement */function btstore_get () {if (empty (BtstoreRoot :: $ root) {BtstoreRoot: $ root = new BtstoreElement (ScriptConf: BTSTORE_ROOT, null);} return BtstoreRoot: $ root ;}

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