When using a recursive function try not to use any iterative loops.
It increases the number of iterations at execution time.
In this example I am trying make a URL using a database and find the actual URL.
Both results are the same but the number of iterations is three times in the 2nd
option.
This is was practically happens :
//correct One
function get_scat_url($temp_catid) {
static $url;
global $site_id=5;
if ($temp_catid != 0) {
$temp_sql=db_query("select sm_cat_id, sm_cat_pcat_id, sm_cat_url, sm_cat_parentid from sitemap_category where sm_cat_id ='". $temp_catid . "' and sm_domain_id ='". $site_id . "'");
if (db_num_rows($temp_sql) > 0) {
$rec_set = db_fetch_array($temp_sql);
$url = $rec_set['sm_cat_url']. " : " . $url;
$temp_catid = $rec_set['sm_cat_parentid'];
get_scat_url($temp_catid);
}
} //first if statement
return $url;
}
?>
//incorrect recursive call in php program
function get_scat_url($temp_catid){
//global $url;
$site_id=5;
while($temp_catid != 0) {
$temp_sql=db_query("select sm_cat_id, sm_cat_pcat_id, sm_cat_url, sm_cat_parentid from sitemap_category where sm_cat_id ='". $temp_catid . "' and sm_domain_id ='". $site_id . "'");
if (db_num_rows($temp_sql) > 0){
$rec_set = db_fetch_array($temp_sql);
$url = $rec_set['sm_cat_url']. " : " . $url;
$temp_catid = $rec_set['sm_cat_parentid'];
get_scat_url($temp_catid);
}
} //while ends here...
return $url;
}
?>