Its a flag and if its value is set to one we must use the longer version of the variable
| Array Name | Longer version of the name |
| $_POST | $HTTP_POST_VARS |
| $_FILES | $HTTP_POST_FILES |
| $_GET | $HTTP_GET_VARS |
| $_COOKIE | $HTTP_COOKIE_VARS |
| $_ENV | $HTTP_ENV_VARS |
| $_SERVER | $HTTP_SERVER_VARS |
| $_SESSION | $HTTP_SESSION_VARS |
Its not at all a convenient option , so its always better to have the value set to off
Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world’s writing systems. Developed in conjunction with the Universal Character Set standard and published in book form as The Unicode Standard, the latest version of Unicode consists of a repertoire of more than 109,000 characters covering 93 scripts, a set of code charts for visual reference, an encoding methodology and set of standard character encodings, an enumeration of character properties such as upper and lower case, a set of reference data computer files, and a number of related items, such as character properties, rules for normalization, decomposition, collation, rendering, and bidirectional display order
Unicode can be implemented by different character encodings. The most commonly used encodings are UTF-8, the now-obsolete UCS-2, and UTF-16. UTF-8 uses one byte for any ASCII characters, which have the same code values in both UTF-8 and ASCII encoding, and up to four bytes for other characters. UCS-2 uses two bytes for each character but cannot encode every character in the current Unicode standard. UTF-16 extends UCS-2, using four bytes to handle each of the additional characters.
Namespaces is a method with which we can group variable,function or objects so that we can have more than one variable or function or object with same name .
Namespaces were introduced into PHP from version 5.3 onwards
Use
• Helps to prevent accidentally re-defining functions, classes, constants, …
• Avoids having to use long, highly descriptive class names
• Constants, classes, traits, interfaces and functions are affeced by the use of namespaces
• Create sub-namespaces to sub-divide a library
Declaring Namespaces
• Must declare the use of namespaces with the keyword “namespace” at the beginning of the code file (right after <?PHP)
• Use one namespace per code file (best practice)
• Unless a namespace is defined, constants, classes, functions, traits and interfaces are defined with the global namespace
• Within a namespace qualifying with a “\” references the global namespace
• Once code elements within a single namespace are defined, they can be used in other php files
Example
<?php
namespace php;
class php
{
public function phpcodez()
{
echo 'Function1 <br />';
}
}
namespace codez;
class codez
{
public function phpcodez()
{
echo 'Function2 <br />';
}
}
$phpcodez = new phpphp();
$phpcodez->phpcodez();
$phpcodez = new codezcodez();
$phpcodez->phpcodez();
?>
<?php echo get_magic_quotes_gpc()?”Enabled”:”Disabled”; ?>
A function is a group of statements that will do certain tasks.
Why Function
When we develop a module in a project , we may need to implement certain tasks(block of statements ) more than once . Writing same block of codes more than once is not at all a good practice . Instead we can give a name to that block and can use them whenever necessary . When we define a block with a name , it is known as function .
• Blocks of code that execute in isolation (and local scope) that perform an action
• Function names are case-insensitive; defined in global scope
• Can be referenced before being defined unless function conditional
• Types: built-in (php supplied); user-defined; externally provided
General Format
function funation_name(){
echo “Error”; // can be on or more lines of statements
}
function – a keyword
funation_name – Any desired name(Should be meaningful)
Once the function is desfined , You can can invoke it by calling its name
<?php funation_name(); ?> // It will print the text “ Error”
A function can have arguments . When a fuction is define using arguments in it , we should pass the values when calling the it .
Example :
function function_sum($a,$b){
echo $a+$b;
}
<?php function_sum(7,8); ?> // It will display 15 as the result .
Note : We should not use any Builtin function name as the function name
A function is a group of statements that can be executed any time you want.
PHP has a number of predefine functions for you to use.
Below given are the different type of funtions available in PHP
It can be considered as a flag that controls how you access form, server, and environment variables. By default this variable is set to Off, requiring you to use special arrays to access these variables. Its values are set in php.ini file .When the value is set to “on” , PHP will dynamically create global variable for many server variable as well as the query string parameters .
Its always better to set the value as “off”
Magic quotes is a controversial feature of the PHP scripting language, which was introduced to help newcomers write functioning SQL commands without requiring manual escaping. It was later described and widely misinterpreted as help to prevent inexperienced developers from writing code which is vulnerable to SQL injection attacks. This feature is officially deprecated as of PHP 5.3.0, and removed in PHP 5.4 due to security concerns
Safe mode is a diagnostic mode of a computer operating system (OS). It can also refer to a mode of operation by application software. Safe mode is intended to fix most, if not all problems within an operating system. It is also widely used for removing Rogue security software.
The PHP safe mode is an attempt to solve the shared-server security problem. It is architecturally incorrect to try to solve this problem at the PHP level, but since the alternatives at the web server and OS levels aren’t very realistic, many people, especially ISP’s, use safe mode for now.