validation
of numbers, 577–582
of text, 582–586
of user input, 568–577
XML, 375–378
value function, Sack framework, 217
values, returning from PHP functions, 518–522
var statement, JavaScript, 60
variable1 property, JavaScript, 149
variable2 property, JavaScript, 149
variable-length argument, 509, 515–518
variables
AUTH_TYPE server variable, $_SERVER, 556
DOCUMENT_ROOT server variable, $_SERVER, 556
GATEWAY_INTERFACE server variable, $_SERVER, 556
global variable, 62
HTTP_ACCEPT server variable, $_SERVER, 556
HTTP_ACCEPT_CHARSET server variable, $_SERVER, 556
HTTP_ACCEPT_ENCODING server variable, $_SERVER, 556
HTTP_ACCEPT_LANGUAGE server variable, $_SERVER, 556
HTTP_CONNECTION server variable, $_SERVER, 557
HTTP_HOST server variable, $_SERVER, 557
HTTP_REFERER server variable, $_SERVER, 557
HTTP_USER_AGENT server variable, $_SERVER, 557
interpolated in strings, 485–487
local variable, 62
loopIndex variable, 77
message variable, JavaScript, 60
overview, 60–62
PATH_TRANSLATED server variable, $_SERVER, 557
PHP_AUTH_PW server variable, $_SERVER, 557
PHP_AUTH_USER server variable, $_SERVER, 557
PHP_SELF server variable, $_SERVER, 557
QUERY_STRING server variable, $_SERVER, 557
REMOTE_ADDR server variable, $_SERVER, 557
REMOTE_HOST server variable, $_SERVER, 557
REMOTE_PORT server variable, $_SERVER, 557
REQUEST_METHOD server variable, $_SERVER, 557
REQUEST_URI server variable, $_SERVER, 557
SCRIPT_FILENAME server variable, $_SERVER, 557
SCRIPT_NAME server variable, $_SERVER, 557
server, 556–560
SERVER_ADMIN server variable, $_SERVER, 557
SERVER_NAME server variable, $_SERVER, 557
SERVER_PORT server variable, $_SERVER, 557
SERVER_PROTOCOL server variable, $_SERVER, 557
SERVER_SIGNATURE server variable, $_SERVER, 557
SERVER_SOFTWARE server variable, $_SERVER, 557
sum variable, JavaScript, 61
variable1 property, JavaScript, 149
variable2 property, JavaScript, 149
working with PHP, 475–485
Void special operator, JavaScript, 65
vprintf string function, PHP, 485
vsprintf string function, PHP, 485