Re: how to update array keys and keep element order ?

On 21 May 2010 13:34, <cr.vegelin@gmail.com> wrote: > > ----- Original Message ----- From: "Richard Quadling" > <rquadling@googlemail.com> > To: <cr.vegelin@gmail.com> > Cc: <php-general@lists.php.net> > Sent: Friday, May 21, 2010 1:30 PM > Subject: Re: [PHP] how to update array keys and keep element order ? > > >> On 21 May 2010 10:56,  <cr.vegelin@gmail.com> wrote: >>> >>> How do I update an array key without disturbing the element order ? >>> Suppose an existing array("FR", values ...) >>> where I want to change 0 => "FR" to "country" => >>> "FR" >>> and keep the original element order. >>> >>> TIA, Cor >>> >> >> Something like ... >> >> function arrayKeyChange(array &$array, $oldKey, $newKey) { >> if (!array_key_exists($oldKey, $array)) { >> trigger_error('Requested key does not exist.', E_USER_WARNING); >> return False; >> } >> if (array_key_exists($oldKey, $array) && array_key_exists($newKey, >> $array)) { >> trigger_error('Will result in duplicate keys.', E_USER_WARNING); >> return False; >> } >> >> // Split keys/values >> $keys = array_keys($array); >> $values = array_values($array); >> >> // Find position of oldKey >> $oldKeyPos = array_search($oldKey, $keys, True); >> >> // Replace key >> $keys[$oldKeyPos] = $newKey; >> >> // Combine keys/values >> $array = array_combine($keys, $values); >> >> return True; >> } > > Thanks Richard, > > I will check your solution. I tried the following: > > function ar_replacekeys ($array, $replacements) > { >    foreach ($array as $key => $value)  // 1) >    { >        foreach ($replacements as $oldkey => $newkey) >        { >            if ($key == $oldkey) >           { >               $array[$newkey] = $value;    // 2) >               unset($array[$key]);              // 2) >           } >        } >    } > } > > Works fine, except that replaced elements are placed at the end. (2) > Also tested: foreach ($array as &$key => $value)    (1) > but this gave "Key element cannot be a reference" > > > > <?php function arrayKeyChange(...){...} // As previously supplied. $arr = array('Continent'=>'Europe', 'FR', 'Currency'=>'Euro'); arrayKeyChange($arr, 0, 'country'); arrayKeyChange($arr, 'country', 'Country'); print_r($arr); ?> outputs ... Array ( [Continent] => Europe [Country] => FR [Currency] => Euro ) -- ----- Richard Quadling "Standing on the shoulders of some very clever giants!" EE : http://www.experts-exchange.com/M_248814.html EE4Free : http://www.experts-exchange.com/becomeAnExpert.jsp Zend Certified Engineer : http://zend.com/zce.php?c=ZEND002498&r=213474731 ZOPA : http://uk.zopa.com/member/RQuadling