Here are the Http Response Codes in php constant
//CONSTANTS
define( 'HTTP_CONTINUE', 100 );
define( 'HTTP_SWITCHING_PROTOCOLS', 101 );
define( 'HTTP_PROCESSING', 102 );
define( 'HTTP_OK', 200 );
define( 'HTTP_CREATED', 201 );
define( 'HTTP_ACCEPTED', 202 );
define( 'HTTP_NON_AUTHORITATIVE', 203 );
define( 'HTTP_NO_CONTENT', 204 );
define( 'HTTP_RESET_CONTENT', 205 );
define( 'HTTP_PARTIAL_CONTENT', 206 );
define( 'HTTP_MULTI_STATUS', 207 );
define( 'HTTP_MULTIPLE_CHOICES', 300 );
define( 'HTTP_MOVED_PERMANENTLY', 301 );
define( 'HTTP_MOVED_TEMPORARILY', 302 );
define( 'HTTP_SEE_OTHER', 303 );
define( 'HTTP_NOT_MODIFIED', 304 );
define( 'HTTP_USE_PROXY', 305 );
define( 'HTTP_TEMPORARY_REDIRECT', 307 );
define( 'HTTP_BAD_REQUEST', 400 );
define( 'HTTP_UNAUTHORIZED', 401 );
define( 'HTTP_PAYMENT_REQUIRED', 402 );
define( 'HTTP_FORBIDDEN', 403 );
define( 'HTTP_NOT_FOUND', 404 );
define( 'HTTP_METHOD_NOT_ALLOWED', 405 );
define( 'HTTP_NOT_ACCEPTABLE', 406 );
define( 'HTTP_PROXY_AUTHENTICATION_REQUIRED', 407 );
define( 'HTTP_REQUEST_TIME_OUT', 408 );
define( 'HTTP_CONFLICT', 409 );
define( 'HTTP_GONE', 410 );
define( 'HTTP_LENGTH_REQUIRED', 411 );
define( 'HTTP_PRECONDITION_FAILED', 412 );
define( 'HTTP_REQUEST_ENTITY_TOO_LARGE', 413 );
define( 'HTTP_REQUEST_URI_TOO_LARGE', 414 );
define( 'HTTP_UNSUPPORTED_MEDIA_TYPE', 415 );
define( 'HTTP_RANGE_NOT_SATISFIABLE', 416 );
define( 'HTTP_EXPECTATION_FAILED', 417 );
define( 'HTTP_UNPROCESSABLE_ENTITY', 422 );
define( 'HTTP_LOCKED', 423 );
define( 'HTTP_FAILED_DEPENDENCY', 424 );
define( 'HTTP_UPGRADE_REQUIRED', 426 );
define( 'HTTP_INTERNAL_SERVER_ERROR', 500 );
define( 'HTTP_NOT_IMPLEMENTED', 501 );
define( 'HTTP_BAD_GATEWAY', 502 );
define( 'HTTP_SERVICE_UNAVAILABLE', 503 );
define( 'HTTP_GATEWAY_TIME_OUT', 504 );
define( 'HTTP_VERSION_NOT_SUPPORTED', 505 );
define( 'HTTP_VARIANT_ALSO_VARIES', 506 );
define( 'HTTP_INSUFFICIENT_STORAGE', 507 );
define( 'HTTP_NOT_EXTENDED', 510 );