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PHP/Variables

2007-01-09T12:23:40Z

203.171.72.130:

Variables, as mentioned briefly in [[Introduction to PHP]], are significant for any programming language. They can be used to store all forms of data, and are generally required to perform multiple manipulations on data not hard-coded into a script. This lesson will introduce the basics of variables in PHP.

== Basic syntax ==
In PHP, all variables are denoted by the $ at the beginning of their identifier. They do not need to be declared; they can simply be assigned a value and used from there on. Variables name should start with a lowercase letter; this is not required but (in certain php configurations) prevents clashes with autoglobals (which will be explained later). Here is a basic example of assigning a value to a variable and printing its value onto the page:

<?php
$message = 'This is the value of the message variable.';
echo $message;
?>

== Variable conversion ==
PHP also automagically switches variable types when needed. For example, all strings (a string is a series of characters) must be enclosed in quotes (both single quotes and double quotes are supported). However, sometimes values you fetch from external sources will be strings by default but need to be treated as ints (short for integers, which are numerical values) for the purpose of a calculation. This example shows how it can be done:

<?php
$input = '42';
$thevalue = $input * pi(); // Will multiply 42 by pi to (by default) 14 decimal places.
echo $thevalue; // This should return something along the lines of 131.946891451
?>

In this instance, we are multiplying the number 42 (in a string variable) by pi to a certain number of decimal places (a float variable - you will learn about this later). Conversion can only occur when possible, however - the following will not work:

<?php
$input = '4string2';
// Should multiply 42 by pi, but will probably post a warning or terminate the script with an error
$thevalue = $input * pi();
// This should return 0 or false, not print anything or even return an error for the previous line
echo $thevalue;
?>

As '4string2' is not a number, PHP will fail to convert it (in order to be multiplied by pi(), which returns a floating point value) and (most likely) return an error or post a warning (depending on PHP's configuration settings in the php.ini file).

== Variable types ==
These are the main types of variables you will be dealing with:

* ''int'' - Short for integer. Holds any integer, i.e. a whole numerical value (no decimal places - however, if an int is assigned a number with a decimal place, it will be converted to a float automatically)
* ''float'' - Abbreviation of floating point value. Holds any integer WITH a decimal place, to a certain precision (generally 32 digits)
* ''double'' - Abbreviation of double precision floating point. Same as above except with far more precision - however, a double value also takes up twice as much memory (generally 8 bytes - obviously insignificant on modern servers)
* ''string'' - Holds any array of characters, i.e. a sentence (or two). Generally has an infinite length; however, for compatibility with older servers, limit the size of strings to 32768 characters.
* ''boolean'' - Can either be true or false, many functions return true or false

== Declaration ==
In a more lower-level language like [[Topic:C++|C++]], the declaration of the type of each variable is needed. For example, the following code in PHP:

<?php
$a = 'Stuff';
?>

Does not explicitly define the type of variable ''a''. Of course, the PHP runtime environment recognizes during execution of this line that the programmer provided a string literal as the value for the variable. If you want to do the same in [[Topic:C++|C++]], you would would have to explicitly declare the variable type:

char[6] a;
a = "Stuff";

Additional equivalent statements combining declaration and initialization of a variable with the same value would be:

char* a = "Stuff"; // using char pointer
char b[] = "Stuff"; // using char array with string literal initialization
char c[] = { 'S', 't', 'u', 'f', 'f', '\0' }; // using char array with array initialization

Notice that C++ requires explicit variable declaration (including variable type) whereas PHP does not. However, it is good practise to declare all variables, as if they are not declared PHP defaults their value to FALSE (0, empty etc.). This is because PHP is a dynamically typed language, and as a result neither type casting nor declaration is enforced. The following is possible:

<?php
var $a;
?>

==Scope==

Scope refers to what can actually modify a variable, e.g:

<?php
$var = 1;
require 'another_page.php';
?>

The page 'another_page.php' has full acess to the variable 'var'.

<?php
$var = 'Test';
function test()
{
echo $var;
}
test();
?>

The above would output nothing, since functions have their own scope, variables outside that scope would not be available.

===Globals===

You can force functions to acess other variables by using the global keyword, e.g:

<?php
$var = 'Test';
function test()
{
global $var;
echo $var;
}
test();
?>

Would output: Test

Or you can use the $GLOBALS array, like this:

<?php
$GLOBALS['var'] = 'Test';
function test()
{
echo $GLOBALS['var'];
}
test();
?>

===Static Variables===

Static variables exist within a function and are saved after the function executes, e.g:

<?php
function increment()
{
static $a = 0;
echo $a;
$a++;
}
increment(); // 0
increment(); // 1
increment(); // 2
increment(); // 3
?>

If the variable 'a' was not static, it would echo 0 each time.

== Referencing ==
On a sidenote, a less used feature of PHP (and, indeed, many lower level programming languages) is memory address referencing. The idea is that every variable is stored at a certain address in memory. Now, say you wanted to have a variable that always remained the same values as another, you could just store point it at the same address - any changes at that address, i.e. any change to the value of the first variable, would be reflected in the other variable (but not vice versa). Examine the following:

<?php
$a = 'Stuff';
$b = &$a; // $b is pointed to $a
$a = 'Stuff2.0'; // $b is now also 'Stuff2.0';
?>

== Learning sessions ==
None available at present.

[[Category:Computer Science]]
[[Category:Computer Programming]]
[[Category:Articles related to php]]

PHP/Variables

2007-01-09T12:22:44Z

203.171.72.130:

Variables, as mentioned briefly in [[Introduction to PHP]], are significant for any programming language. They can be used to store all forms of data, and are generally required to perform multiple manipulations on data not hard-coded into a script. This lesson will introduce the basics of variables in PHP.

== Basic syntax ==
In PHP, all variables are denoted by the $ at the beginning of their identifier. They do not need to be declared; they can simply be assigned a value and used from there on. Variables name should start with a lowercase letter; this is not required but (in certain php configurations) prevents clashes with autoglobals (which will be explained later). Here is a basic example of assigning a value to a variable and printing its value onto the page:

<?php
$message = 'This is the value of the message variable.';
echo $message;
?>

== Variable conversion ==
PHP also automagically switches variable types when needed. For example, all strings (a string is a series of characters) must be enclosed in quotes (both single quotes and double quotes are supported). However, sometimes values you fetch from external sources will be strings by default but need to be treated as ints (short for integers, which are numerical values) for the purpose of a calculation. This example shows how it can be done:

<?php
$input = '42';
$thevalue = $input * pi(); // Will multiply 42 by pi to (by default) 14 decimal places.
echo $thevalue; // This should return something along the lines of 131.946891451
?>

In this instance, we are multiplying the number 42 (in a string variable) by pi to a certain number of decimal places (a float variable - you will learn about this later). Conversion can only occur when possible, however - the following will not work:

<?php
$input = '4string2';
// Should multiply 42 by pi, but will probably post a warning or terminate the script with an error
$thevalue = $input * pi();
// This should return 0 or false, not print anything or even return an error for the previous line
echo $thevalue;
?>

As '4string2' is not a number, PHP will fail to convert it (in order to be multiplied by pi(), which returns a floating point value) and (most likely) return an error or post a warning (depending on PHP's configuration settings in the php.ini file).

== Variable types ==
These are the main types of variables you will be dealing with:

* ''int'' - Short for integer. Holds any integer, i.e. a whole numerical value (no decimal places - however, if an int is assigned a number with a decimal place, it will be converted to a float automatically)
* ''float'' - Abbreviation of floating point value. Holds any integer WITH a decimal place, to a certain precision (generally 32 digits)
* ''double'' - Abbreviation of double precision floating point. Same as above except with far more precision - however, a double value also takes up twice as much memory (generally 8 bytes - obviously insignificant on modern servers)
* ''string'' - Holds any array of characters, i.e. a sentence (or two). Generally has an infinite length; however, for compatibility with older servers, limit the size of strings to 32768 characters.
* ''boolean'' - Can either be true or false, many functions return true or false

== Declaration ==
In a more lower-level language like [[Topic:C++|C++]], the declaration of the type of each variable is needed. For example, the following code in PHP:

<?php
$a = 'Stuff';
?>

Does not explicitly define the type of variable ''a''. Of course, the PHP runtime environment recognizes during execution of this line that the programmer provided a string literal as the value for the variable. If you want to do the same in [[Topic:C++|C++]], you would would have to explicitly declare the variable type:

char[6] a;
a = "Stuff";

Additional equivalent statements combining declaration and initialization of a variable with the same value would be:

char* a = "Stuff"; // using char pointer
char b[] = "Stuff"; // using char array with string literal initialization
char c[] = { 'S', 't', 'u', 'f', 'f', '\0' }; // using char array with array initialization

Notice that C++ requires explicit variable declaration (including variable type) whereas PHP does not. However, it is good practise to declare all variables, as if they are not declared PHP defaults their value to FALSE (0, empty etc.). This is because PHP is a dynamically typed language, and as a result neither type casting nor declaration is enforced. The following is possible:

<?php
var $a;
?>

==Scope==

Scope refers to what can actually modify a variable, e.g:

<?php
$var = 1;
require 'another_page.php';
?>

The page 'another_page.php' has full acess to the variable 'var'.

<?php
$var = 'Test';
function test()
{
echo $var;
}
test();
?>

The above would output nothing, since functions have there own scope, variables outside that scope would not be available.

===Globals===

You can force functions to acess other variables by using the global keyword, e.g:

<?php
$var = 'Test';
function test()
{
global $var;
echo $var;
}
test();
?>

Would output: Test

Or you can use the $GLOBALS array, like this:

<?php
$GLOBALS['var'] = 'Test';
function test()
{
echo $GLOBALS['var'];
}
test();
?>

===Static Variables===

Static variables exist within a function and are saved after the function executes, e.g:

<?php
function increment()
{
static $a = 0;
echo $a;
$a++;
}
increment(); // 0
increment(); // 1
increment(); // 2
increment(); // 3
?>

If the variable 'a' was not static, it would echo 0 each time.

== Referencing ==
On a sidenote, a less used feature of PHP (and, indeed, many lower level programming languages) is memory address referencing. The idea is that every variable is stored at a certain address in memory. Now, say you wanted to have a variable that always remained the same values as another, you could just store point it at the same address - any changes at that address, i.e. any change to the value of the first variable, would be reflected in the other variable (but not vice versa). Examine the following:

<?php
$a = 'Stuff';
$b = &$a; // $b is pointed to $a
$a = 'Stuff2.0'; // $b is now also 'Stuff2.0';
?>

== Learning sessions ==
None available at present.

[[Category:Computer Science]]
[[Category:Computer Programming]]
[[Category:Articles related to php]]

Archive:Fanboy

2006-04-06T11:32:31Z

203.171.91.94: /* Video game fanboys */

'''Fanboy''' or '''fanboi''' is a term used to describe a male who is utterly devoted to a single subject or [[hobby]], often to the point where it is considered an [[obsession]].

==History of fanboys and the term==
The term originated in [[comic book]] circles, to describe someone who immersed himself in the fictional worlds of comics and the culture of comics fandom, to the exclusion of a more mainstream social life. The term is often used in a derogatory manner by other less obsessed fans. In the songs of the fannish [[parody]] [[musician]] [[Luke Ski]], many characters proudly consider themselves ''fanboys''. The term is most commonly associated with adolescent and teen males but can be applicable to any age or sex. Common subjects of reverence by fanboys are [[TV show]]s, [[film|movie]]s, [[anime]], [[car]]s, [[video game console]]s, [[video games]], [[operating system]]s, [[MMORPG]]s, and [[software]] companies.

The stereotypical image of the fanboy is as an unkempt, socially awkward, young man who may be perceived as a loud mouthed [[pseudo-intellectual]]. A popular depiction of this stereotype is the [[Comic Book Guy]] on ''[[The Simpsons]]''. In the mid [[1990s]], the emergence of [[slacker]] culture changed this image somewhat. Movies such as [[Kevin Smith]]'s Jersey Trilogy (''[[Clerks]]'', ''[[Mallrats]]'', and ''[[Chasing Amy]]''), altered the image of the fanboy{{fact}}. As electronic entertainment gained popularity, the term became increasingly applied to video gamers and television addicts who readily labelled themselves.

The earliest use of the word "fanboy" has been dated to 1982, to the cover of the "Official Underground and Newave Comix Price Guide". On this cover page are sketched overweight, overzealous comic book collectors wearing T-shirts that state "Fanboys of America," and are describing the extreme measures they would go to, including moving to San Francisco, to preserve their comics.

Fanboys can be zealously committed to their particular narrow area of interest, to the exclusion and derision of competing or similar products, regardless of their merits. Fanboys are often perceived as possessing a [[sycophant]]ic devotion to the creators behind the object of their passion. An obsession may be short or long term and, at times, aggressively defended. One example of this is [[Harry Knowles]] and his associates at [[Ain't It Cool News]], whose particular focus is on [[film|movies]] in the [[action movie|action]], [[fantasy]], adventure and [[superhero]] genres. Fanboys are noted for a very emotional attachment to their chosen subject, often taking negative remarks about it as a personal attack. They may readily engage in debates, but will fall back on emotional responses. For example, a "fanboy" may go out of their way to point out negative and often untrue statements about their obsession's rivals; this is commonly known as [[fear, uncertainty and doubt|FUD]].

More recently, especially in the [[video game industry]], fans of a particular [[video game console]] manufacturer have begun exhibiting slavish devotion to their brand of choice. Conversely they hold an unreasonable amount of animosity towards the other brands which they consider to be competition. They are extremely rude to fans of the other companies or even people who don’t hail complete and utter devotion to the object of their fanaticism. These people seek out every opportunity to annoy others whose opinions differ from theirs. This trend has led to the term “fanboy” deriving a more and more negative connotation.

==Some common types of fanboys==
===Video game fanboys===
After comic books, video games may be the most fruitful environment for fanboys. These include:
*[[Nintendo]] Fanboys (sometimes called a "Ninty" or "Drone", short for "Nintendrone", also "Nintendophile")
*[[Sony]] Fanboys (sometimes called "Tools", short for "PSTool" which is derived from Sony's current entertainment console, the [[PS2]])
*[[Xbox]] Fanboys ( not usually called fannoys, sometimes called "Xbots")
*[[Sega]] Fanboys
*[[Final Fantasy]] Fanboys (want the series to continue forever)

On the [[GameSpot]] System Wars forum, as well as SystemWars.com [http://www.systemwars.com/forums/], the different schools of video game fanboys are associated with various animals. Nintendo fanboys are called "[[sheep]]" because of their perceived willingness to be herded by Nintendo. Sony fanboys are called "[[Cattle|cows]]" because of the perception they pay extra, i.e. are "milked" by Sony for optional features for their equipment of choice. Microsoft fanboys are called "[[Lemming|lemmings]]" because of the perception they follow Microsoft blindly, even if it leads to their demise. Similarly, PC fanboys are called "[[hermits]]" because they are perceived as solitary, friendless gamers who play by themselves.

===Anime fanboys===
Anime is another fertile breeding ground for fanboys. Some notable examples are:
*[[Dragon Ball]] Fanboys (get hung up on names, especially [[romanji]])
*[[Sailor Moon]] Fanboys (very strict about [[manga]] continuity)
*[[Inuyasha]] Fangirls (generally, they're all [[female]], but display all the traits of fanboys)

===Computer software/hardware fanboys===
* [[Linux]] Fanboys - Love open source and believe that anything coming from Microsoft is inferior.
* [[Mac]] Fanboys - Devoted to the Mac design concept and think all Apple products are amazing. Were advocates of the superiority of [[PowerPC]] architecture over [[X86 architecture|X86]] until the move to Intel processors in 2005.
* [[Microsoft]] Fanboys - Love Windows' ease-of-use and all Microsoft stuff.
* [[ATI Technologies|ATI]] Fanboys - Often boast that their graphics cards have greater image quality. Refer to [[Nvidia]] fans as "Nvidiots".
* [[Nvidia]] Fanboys - Refer to [[ATI Technologies|ATI]] fans as "FanATIcs" (should not be confused with AEG sponsored posters, who receive indirect compensation as a reward to subtle promotion of NVidia's products)
* [[Google]] Fanboys - Devoted to the corporation that produced the Google.com search engine. They are ceaselessly bullish on Google's future, insist that Google will eventually unseat Microsoft as the most dominant technology company, consider Google's stock a bargain at any price and tirelessly argue against any insinuation that Google is ignoring its self-proclaimed mandate to "Do No Evil."

==In Media==
===Comic Book===
*[[Sergio Aragonés]]' ''Fanboy''

===Television===
*[[The Simpsons]]' [[Comic Book Guy]]

===Radio/Podcasts===
*[[Fanboy Radio]] - [http://fanboyradio.com]
*Drooling FanBoy - [http://droolingfanboy.com]

===Webcomics===
*[[Fanboy Almanac (webcomic)]] - [http://fanboyalmanac.com Fanboy Almanac]
*[http://www.ngeb.net/fanboys Fanboys web comic]

==See also==
* [[addiction]]
* [[otaku]]
* [[anorak (slang)|anorak]]

[[Category:Fandom]]

[[de:Fanboy]]