<?php

$codes = array();
$headers = array("HTTP/1.1 100 Continue",
"HTTP/1.1 302 Found",
"HTTP/1.1 200 OK",
"HTTP/1.1 400 Not Found");

foreach ($headers AS $header) {
    list($http, $code, $status) = explode(" ", $header, 2);
    $codes[$code] = $status;
}

print_r($codes);

?>