Php strcmp和数组

I have a php array. In 5th position I have a string "A". When I use var_dump($myarray[4]) I have string(38) "A". I would to compare this value, so I try this code:

if (strcmp($myarray[4], "A") == 0) {
    echo 'OK';
}

but I do I never get a true condition. If I try to print strcmp($myarray[4], "A") I get -5 why??