Notes

==>php - Server side scription language
==>php - Hypertext Preprocessor - executes and return output in the form of html - Rasmus ledorf (xml . odf , csv . flash , text)
==>basic syntax : <?php ?> terminate code with ;
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==>comments : 1) not executed by compiler 2) let other know what's the code for ?
// , # , /* */
==>Sensitivity : all keywords , classes , function , user defined function are not case sensitive but variables are case sensitive.
==>variables : Variables are "containers" for storing information.php variables need not to declare(automatic)
$value = "fdfdf";
===>Scop of varible .. local , global , static ==> global $y; or $GLOBALS['y']
=>A variable declared within a function has a LOCAL SCOPE and can only be accessed within that function:
=>A variable declared outside a function has a GLOBAL SCOPE and can only be accessed outside a function:
=>Normally, when a function is completed/executed, all of its variables are deleted. However, sometimes we want a local variable NOT to be deleted. We need it for a further job.
To do this, use the static keyword when you first declare the variable:
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==output statements ==
1) echo 2) print --
===>- echo is faster that print
- echo does not have return value , print returns 1
- echo can user multiple parameter print could not
Ex 1: print "<h2>PHP is Fun!</h2>"; /* Ex 2 */ echo "<h2>PHP is Fun!</h2>";
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--Datatypes in php --
1)String 2)Integer 3)Float (floating point numbers - also called double)
5)Boolean 6)Array 7)Object 8)NULL 9)Resource

String is sequence of characters in single or double quotes
Integer is any non decimal number
array single variable has multiple values
float - decimal number
object -real time entities which has state and properties
$cars = array("Volvo","BMW","Toyota");
$herbie = new Car(); //car is class
null -NULL
If a variable is created without a value, it is automatically assigned a value of NULL.