XOR swap algorithm


Conventional swapping requires the use of a temporary storage variable. Using the XOR swap algorithm, however, no temporary storage is needed. The algorithm is as follows:

X := X XOR Y
Y := X XOR Y
X := X XOR Y

To understand it, think about the PLUS swap algorithm
a = a + b
b = a – b
a = a -b

interpret XOR: it is a binary PLUS operation without carry.

stored routine


A stored routine is either a procedure or a function. Stored routines are created with the CREATE PROCEDURE and CREATE FUNCTION statements (see Section 13.1.9, “CREATE PROCEDURE and CREATE FUNCTION Syntax”). A procedure is invoked using a CALL statement (see Section 13.2.1, “CALL Syntax”), and can only pass back values using output variables. A function can be called from inside a statement just like any other function (that is, by invoking the function’s name), and can return a scalar value. The body of a stored routine can use compound statements (see Section 13.6, “MySQL Compound-Statement Syntax”).


“ A stored routine is a set of SQL statements that can be stored in the server.”

routine pros/cons and syntax there


routine examples there


HtmlUnit is a headless web browser written in Java. It allows high-level manipulation of websites from other Java code, including filling and submitting forms and clicking hyperlinks. It also provides access to the structure and the details within received web pages. HtmlUnit emulates parts of browser behaviour including the lower-level aspects of TCP/IP and HTTP. A sequence such as getPage(url), getLinkWith("Click here"), click() allows a user to navigate through hypertext and obtain web pages that include HTML, JavaScript, Ajax and cookies. This headless browser can deal with HTTPS security, basic http authentication, automatic page redirection and other HTTP headers. It allows Java test code to examine returned pages either as text, an XML DOM, or as collections of forms, tables, and links.[1]

The most common use of HtmlUnit is test automation of web pages, but sometimes it can be used for web scraping, or downloading website content.


Broadband Wireless Dongles

Wireless broadband dongles work by communicating with a mobile mast and mobile network rather than connecting to another wireless device like the normal wireless dongle. This means that you can wirelessly connect to the internet from any location that has a mobile signal.

How Does it Work

Wireless dongles work by transmitting and receiving a wireless signal to another device that is listening for the signal transmission.


In computing, word is a term for the natural unit of data used by a particular processor design. A word is basically a fixed-sized group of bits that are handled as a unit by the instruction set and/or hardware of the processor. The number of bits in a word (the word size, word width, or word length) is an important characteristic of any specific processor design or computer architecture.

modern general purpose computers usually use word size of 32 or 64 bits.