Cookie A special object containing state/status information about the client that can be accessed by the server. Included in that state object is a description of the range of URLs for which that state is valid. Future HTTP requests from the client falling within a range of URLs described within the state object will include transmission of the current value of the state object from the client back to the server. This simple form of data storage allows the server to provide personalized service to the client. Online merchants can store information about items currently in an electronic shopping basket, services can post registration information and automate functions such as typing a user ID, and user preferences can be saved on the client and retrieved by the server when the site is contacted. For limited-use information, such as shopping services, it is also possible to set a time limit on the life of the cookie information.
CGI scripts are typically used to set and retrieve cookie values. To generate the cookie requires sending an HTTP header in the following format:
Set-Cookie: NAME=Value; [EXPIRES=date;] [PATH=pathname;] [DOMAIN=domainname;] [SECURE]
When a request for cookie information is made, the list of cookie information is searched for all URLs which match the current URL. Any matches are returned in this format:
cookie: NAME1=string1; NAME2=string2; ...
Cookie was an arbitrarily assigned name. For more information about the cookie and its function, see http://home.netscape.com/newsref/std/cookie_spec.html.
Function A user-defined or built-in set of statements that perform a task. It can also return a value when used with the return statement.
Hierarchy Navigator objects exist in a set relation to each other that reflects the structure of an HTML page. This is referred to as instance hierarchy because it only works with specific instances of objects, rather than general classes. The window object is the parent of all other Navigator objects. Underneath window, location, history, and document all share precedence. Document includes forms, links, and anchors.
Each object is a descendant of the higher object. A form called orderForm is an object, but is also a property of document. As such, it is referred to as document.orderForm.
Java An object-oriented, platform-independent programming language developed by Sun Microsystems and used to add additional functionality to Web pages. Programming in Java requires a Java Development Kit with compiler and core classes. Although Java started out as a language intended for writing Web applets, more and more stand-alone Java applications are being created.
Literal An absolute value not assigned to a variable. Examples include 1, 3.1415927, "Bob", true.
Method A function assigned to an object. For example, bigString.toUpperCase() returns an uppercase version of the string contained in bigString.
Both object and property names are case sensitive.
Operator Performs a function on one or more operands or variables. Operators are divided into two classes: binary and unary. Binary operators need two operands, and unary operands can operate on a single operand. For example, addition is a binary operand:
sum = 1 + 1
Unary operands are often used to update counters. The following example increases the variable by 1:
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