PHP Introduction

What is PHP?

PHP is an HTML-embedded scripting language.First version of PHP was developed by Rasmus Lerdorf in 1994.

§ PHP is a recursive acronym for “PHP:Hypertext Preprocessor”. PHP is a programming langauage allows web developers to create dynamic web pages.

§ PHP is a widely used open source scripting language that is especially suited for web development.It is used to manage dynamic content,session tracking,databases,even built entire e-commerce sites.

§ PHP is a scripting language ,like HTML.That means its code does not need to be compiled.

§ PHP is free .Download it from www.php.net

§ PHP syntax is C-like.

Uses of PHP

Using PHP you can create,delete,insert,modify within your database.
PHP can send and receive cookies.
PHP can can generate dynamic page.
Using php, you can restrict users to access some pages of your websites.
It can encrypt data

PHP Operator

PHP supports following types of operator:

· Arithmetic Operators

· Assignment Operators

· Comparision Operators

· Increment/Decrement Operators

· Logical Operators

· String Operators

· Array Operators

Arithmetic Operator:

Let the value of $x = 10 & $y = 20.Now let’s perform some arithmetic operation:

Operator	Name	Example	Result
‘+’	Addition	$x + $y	30
‘-’	Subtraction	$x - $y	-10
‘*’	Multiplication	$x * $y	200
‘/’	Division	$x / $y	2
‘%’	Modulus	$x % $y	0

PHP Assignment Operators:

There are some assignment operators supported by PHP:

Let the value of $x = 10 .Now let’s perform some Assignment operation:

Assignment	Also written as	Description	Result
x=y	x=y	The left operand get the value of right operand.	10
x+=y	x=x+y	Addition:$x=10 $x+=100; echo $x	120
x-=y	x=x-y	Subtraction:$x=10 $x-=100; echo $x	-90
x*=y	x=x*y	Multiplication:$x=10 $x*=100; echo $x	1000
x/=y	x=x/y	Division:$x=10 $x/=5; echo $x	2
x%=y	x=x%y	Modulus:$x=15 $x%=4; echo $x	3

PHP Comparision Operators:

PHP Comparision operators are used to compare two values.these value can be number or string.

Operator	Name	Example	Result
==	Equal	$a==$b	Returns true if $a is equal to $b.
===	Identical	$a===$b	Returns true,if $a is equal to $b along with same data type.
!=	Not equal	$a!=$b	Returns true if $a is not equal to $b
<>	Not equal	$a<>$b	Returns true if $a is not equal to $b
!==	Not identical	$a!==$b	Returns true,if $a is not equal to $b and not of same data type.
>	Greater than	$a>$b	Returns true if $a is greater than to $b
<	Less than	$a<$b	Returns true if $a is less than to $b
>=	Greater than or equal	$a>=$b	Returns true if $a is greater or equal to $b
<=	Less than or equal	$a<=$b	Returns true if $a is less or equal to $b

PHP Increment/Decrement Operators:

Let the value of $a=10

Operator	Name	Description	Result
++$a	Pre-increment	Increment $a by 1, than return the value	11
$a++	Post-increment	Return value,than increment by 1	10
--$a	Pre-decrement	Decrement by 1,than return the value	9
$a--	Post-decrement	Return value,than decrement	10

PHP Logical Operator

These operators are used to combine conditional statements.

Operator	Name	Example	Result
and	And	$a and $y	True if both $a and $b are true
or	Or	$a or $b	True if either $a or $b is true
xor	Xor	$a xor $b	True if either $a or $b is true but not both
&&	And	$a && $b	True if both $a and $b are true
\|\|	Or	$a \|\| $b	True if either $a or $b is true
!	Not	$a!	True if $a is not true

PHP string Operators

These operators are used specially in strings.

Operator	Name	Example	Result
.	Concatenation	$a.$b	Concatination of $a and $b
.=	Concatination assignment	$a.=$b	Append $b to $a

PHP Array Operators

These array operators are used to compare.

Operator	Name	Result	Example
+	Union	$a + $b	Union of $a and $b
==	Equality	$a == $b	Returns true if $a and $b have same key/value
===	Identity	$a===$b	Returns true if $a and $b have same key/value In same order and same type
!=	Inequality	$a != $b	Returns true if $a is not equal to $b
<>	Inequality	$a <> $b	Returns true if $a is not equal to $b
!==	Non-identity	$a !== $b	Returns true if $a is not identical to $b

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