Question:Write the name of 9 Superglobal Variables______. 

"$_GET[ ], $_POST[ ], $_REQUEST[ ], $_SERVER[ ], $_SESSION[ ], $GLOBAL[ ], $_COOKE[ ], $_FILES[ ], $_ENV[ ], "

Question:Write some of PHP benefits compare to other language? 

- PHP runs on different platforms (Windows, Linux, Unix, etc.)
- PHP is compatible with almost all servers used today (Apache, IIS, etc.)
- PHP is FREE to download from the official PHP resource: www.php.net
- PHP is easy to learn and runs efficiently on the server side

Question:What is a PHP File? 

- PHP files may contain text, HTML tags and scripts
- PHP files are returned to the browser as plain HTML
- PHP files have a file extension of ".php", ".php3", or ".phtml"

Question:Between echo () and print () functions which one is the faster and why? 

The echo () function is a tad faster than print() function, because it returns nothing, whereas print() function returns 1 if the statement is successfully output.

Question:What is PHP? 

- PHP stands for PHP: Hypertext Preprocessor
- PHP is a server-side scripting language, like ASP
- PHP scripts are executed on the server
- PHP supports many databases (MySQL, Informix, Oracle, Sybase, Solid, PostgreSQL,
Generic ODBC, etc.)
- PHP is an open source software (OSS)
- PHP is free to download and use

Question: What are type casting and juggling? 

Ans:  Type casting:  converting values from one data type to another is known as type casting.
         Juggling: Automatic conversion is known as type juggling.

Question:What are the different types of errors in PHP? 

1. Notices: These are trivial, non-critical errors that PHP encounters while executing a script - for example,
accessing a variable that has not yet been defined. By default, such errors are not displayed to the user at all
- although you can change this default behavior.2. Warnings: These are more serious errors - for example, attempting to include() a file which does not exist.
By default, these errors are displayed to the user, but they do not result in script termination.3. Fatal errors: These are critical errors - for example, instantiating an object of a non-existent class, or calling
a non-existent function. These errors cause the immediate termination of the script, and PHP’s default
behavior is to display them to the user when they take place.

Question:Between echo () and print () functions which one is the faster and why?

 

The echo () function is a tad faster because it returns nothing, whereas print() will return 1 if the statement is successfully output.

Question:What are type casting and juggling? 

Casting: Converting values from one data type to another is known as type casting. This is accomplished by placing the intended type in front of the variable to be cast.example:
$x=34.54;
$y=(int)$x;
echo $y; // returns 34Juggling: Variables are sometimes automatically cast to best fit the circumstances in which they are referenced. This is known as Type Juggling.example:
$a="34 items"
$total=5;
$total+=$a;
echo $total;// returns 39

Question:What is constant? How can you declare a constant? 

A constant is a value that cannot be modified throughout the execution of a program. Constants are particularly useful when working with values that definitely will not require modification, such as Pi (3.141592). Once a constant has been defined, it cannot be changed (or redefined) at any other point of the program. Constants are defined using the define() function in php.