PHP string comparison, === or strcmp not working -

i have hash map contains keys sorted versions of values. example,

$hash = array( "abc" => "cab",                "aas" => "sas"         ); 

i have array of sorted strings($sorted_words) , want compare these strings keys of above hash map , if match found, store corresponding value in string. use === , strcmp(), neither works. says strings didn't match. here code :

foreach($sorted_words $sc) {     foreach($hash $key => $value) {         if(strcmp($sc, $key) == 0) { // or if($sc === $key)             $string_match .= $value; // store corresponding value matched key.         }     } } 

but comparison fails strcmp() returns greater 1 , '===' never returns true. can tell what's wrong ? i'm pretty sure there strings match.

try :

$string_match  = ""; foreach($sorted_words $sc) {    if(array_key_exists($sc, $hash)){       $string_match .=  $hash[$sc];    }  }