2. P H P
• PHP is a server scripting language, and a powerful tool for making
dynamic and interactive Web pages.
What is PHP?
• PHP is an acronym for "PHP: Hypertext Preprocessor"
• PHP is a widely-used, open source scripting language
• PHP scripts are executed on the server
• PHP is free to download and use
What is a PHP File?
• PHP files have extension ".php"
3. WHAT CAN PHP DO?
• PHP can generate dynamic page content
• PHP can create, open, read, write, delete, and close files on the server
• PHP can collect form data
• PHP can send and receive cookies
• PHP can add, delete, modify data in your database
• PHP can be used to control user-access
• PHP can encrypt data
4. P H P S Y N T A X P H P C O M M E N T S
<html>
<body>
<h1>My first PHP page</h1>
<?php
echo "Hello World!";
?>
</body>
</html>
// Outputs a welcome message:
echo "Welcome Home!";
Multi-line Comments
Multi-line comments start with /* and end with */.
Any text between /* and */ will be ignored.
5. PHP VARIABLES
• A variable starts with the $ sign, followed by the name of the variable
• A variable name must start with a letter or the underscore character
• A variable name cannot start with a number
• A variable name can only contain alpha-numeric characters and underscores
• Variable names are case-sensitive
Example- $x = 5;
$y = "John"
6. P H P VA R I A B L E S S C O P E
The scope of a variable is the part of the script where the variable can be referenced/used.
PHP has three different variable scopes:
• local
• global
• static
7. GLOBAL AND LOCAL SCOPE
• A variable declared outside a function has a GLOBAL SCOPE and can only be accessed outside
a function.
Global Scope
<?php
$x = 5; // global scope
function myTest() {
// using x inside this function will generate an error
echo "<p>Variable x inside function is: $x</p>";
}
myTest();
echo "<p>Variable x outside function is: $x</p>";
?>
Output - Variable x inside function is:
Variable x outside function is: 5
8. LOCAL SCOPE
<?php
function myTest() {
$x = 5; // local scope
echo "<p>Variable x inside function is: $x</p>";
}
myTest();
// using x outside the function will generate an error
echo "<p>Variable x outside function is: $x</p>";
?>
Output - Variable x inside function is: 5
Variable x outside function is:
9. P H P E C H O A N D P R I N T S T A T E M E N T S
echo and print are more or less the same.They are both used to output data to the screen.
• The differences are small: echo has no return value while print has a return value of 1 so it can be
used in expressions.
• echo can take multiple parameters (although such usage is rare) while print can take one
argument. echo is marginally faster than print.
10. P H P D A T A T Y P E S
Variables can store data of different types, and different data types can do different
things.
PHP supports the following data types:
• String
• Integer
• Float (floating point numbers - also called double)
• Boolean
• Array
• NULL
11. P H P S T R I N G
A string is a sequence of characters, like "Hello world!“.
<?php
$x = "Hello world!";
$y = 'Hello world!';
var_dump($x);
echo "<br>";
var_dump($y);
?>
Output - string(12) "Hello world!"
string(12) "Hello world!"
12. P H P I N T E G E R
• An integer must have at least one digit
• An integer must not have a decimal point
• An integer can be either positive or negative
• Integers can be specified in: decimal (base 10), hexadecimal (base 16), octal (base 8), or binary
(base 2) notation
<?php
$x = 5985;
var_dump($x);
?>
Output - int(5985)
13. PHP FLOAT
• A float (floating point number) is a number with a decimal point or a number in exponential form.
• In the following example $x is a float.The PHP var_dump() function returns the data type and
value:
<?php
$x = 10.365;
var_dump($x);
?>
Output - float(10.365)
14. PHP BOOLEAN
A Boolean represents two possible states:TRUE or FALSE.
<html>
<body>
<?php
$x = true;
var_dump($x);
?>
</body>
</html>
Output - bool(true)
15. P H P A R R A Y
• An array stores multiple values in one single variable.
• In the following example $cars is an array.The PHP var_dump() function returns the data type
and value:
<?php
$cars = array("BMW","Toyota");
var_dump($cars);
?>
Output –
array(2) { [0]=> string(3) "BMW" [1]=> string(6) "Toyota" }
16. P H P C A S T I N G
Change DataType
Casting in PHP is done with these statements:
(string) - Converts to data type String
(int) - Converts to data type Integer
(float) - Converts to data type Float
(bool) - Converts to data type Boolean
(array) - Converts to data type Array
(object) - Converts to data type Object
(unset) - Converts to data type NULL
17. <?php
$a="first step";
$b="2";
$c="true";
$d="3.89";
$f="null";
$a= (string) $a;
$b= (array) $b;
$c= (bool) $c;
$d= (float) $d;
$f= (string) $f;
//To verify the type of any object in PHP, use
the var_dump() funtion:
var_du($a);
echo"<br>";
var_dump($b);
echo"<br>";
var_dump($c);
echo"<br>";
var_dump($d);
echo"<br>";
var_dump($f);
?>
OUTPUT :
string(10) "first step"
array(1) { [0]=> string(1) "2" }
bool(true)
float(3.89)
string(4) "null"
18. P H P C O N S T A N T S
• Constants are like variables, except that once they are defined they cannot be
changed or undefined.
• A constant is an identifier (name) for a simple value. The value cannot be changed
during the script.
• A valid constant name starts with a letter or underscore (no $ sign before the constant
name)
Syntax:
define(name, value, case-insensitive);
19. P H P O P E R ATO R S
Operators are used to perform operations on variables and values.
PHP divides the operators in the following groups:
• Arithmetic operators
• Assignment operators
• Comparison operators
• Increment/Decrement operators
• Logical operators
• String operators
• Array operators
• Conditional assignment operators
20. PHP ARITHMETIC OPERATORS
The PHP arithmetic operators are used with numeric values to perform common
arithmetical operations, such as addition, subtraction, multiplication etc.
Operator Name Example Result
+ Addition $x + $y Sum of $x and $y
- Subtraction $x - $y Difference of $x and $y
* Multiplication $x * $y Product of $x and $y
/ Division $x / $y Quotient of $x and $y
% Modulus $x % $y Remainder of $x divided by $y
** Exponentiation $x ** $y Result of raising $x to the $y'th power
21. P H P A S S I G N M E N T O P E R AT O R S
The PHP assignment operators are used with numeric values to write a value to
a variable
Assignment Same as... Description
x = y x = y The left operand gets set to the value of the expression on the
right
x += y x = x + y Addition
x -= y x = x - y Subtraction
x *= y x = x * y Multiplication
x /= y x = x / y Division
x %= y x = x % y Modulus
22. P H P C O M PA R I S O N O P E R ATO R S
The PHP comparison operators are used to compare two values (number or string):
Operator Name Example Result
== Equal $x == $y Returns true if $x is equal to $y
=== Identical $x === $y Returns true if $x is equal to $y, and they are of the same
type
!= Not equal $x != $y Returns true if $x is not equal to $y
<> Not equal $x <> $y Returns true if $x is not equal to $y
!== Not identical $x !== $y Returns true if $x is not equal to $y, or they are not of the
same type
> Greater than $x > $y Returns true if $x is greater than $y
< Less than $x < $y Returns true if $x is less than $y
>= Greater than or equal to $x >= $y Returns true if $x is greater than or equal to $y
<= Less than or equal to $x <= $y Returns true if $x is less than or equal to $y
<=> Spaceship $x <=> $y Returns an integer less than, equal to, or greater than zero,
depending on if $x is less than, equal to, or greater than $y.
Introduced in PHP 7.
23. PH P IN CR E ME N T / D E CRE M EN T O PE R ATOR S
The PHP increment operators are used to increment a variable's value.
The PHP decrement operators are used to decrement a variable's value
Operator Same as... Description
++$x Pre-increment Increments $x by one, then returns $x
$x++ Post-increment Returns $x, then increments $x by one
--$x Pre-decrement Decrements $x by one, then returns $x
$x-- Post-decrement Returns $x, then decrements $x by one
24. P H P L O G I C A L O P E R AT O R S
The PHP logical operators are used to combine conditional statements.
Operator Name Example Result
and And $x and $y True if both $x and $y are true
or Or $x or $y True if either $x or $y is true
xor Xor $x xor $y True if either $x or $y is true, but not
both
&& And $x && $y True if both $x and $y are true
|| Or $x || $y True if either $x or $y is true
! Not !$x True if $x is not true
25. P H P S T R I N G O P E R AT O R S
PHP has two operators that are specially designed for strings.
Operator Name Example Result
. Concatenation $txt1 . $txt2 Concatenation of $txt1 and $txt2
.= Concatenation
assignment
$txt1 .= $txt2 Appends $txt2 to $txt1
26. P H P A R R AY O P E R ATO R S
The PHP array operators are used to compare arrays.
Operator Name Example Result
+ Union $x + $y Union of $x and $y
== Equality $x == $y Returns true if $x and $y have the same
key/value pairs
=== Identity $x === $y Returns true if $x and $y have the same
key/value pairs in the same order and of the
same types
!= Inequality $x != $y Returns true if $x is not equal to $y
<> Inequality $x <> $y Returns true if $x is not equal to $y
!== Non-identity $x !== $y Returns true if $x is not identical to $y
27. P H P C O N D I T I O N A L A S S I G N M E N T O P E R ATO R S
The PHP conditional assignment operators are used to set a value depending on
conditions:
Operator Name Example Result
?: Ternary $x
= expr1 ? expr2 : e
xpr3
Returns the value of $x.
The value of $x is expr2 if expr1 =
TRUE.
The value of $x is expr3 if expr1 =
FALSE
?? Null coalescing $x = expr1 ?? expr2 Returns the value of $x.
The value of $x
is expr1 if expr1 exists, and is not
NULL.
If expr1 does not exist, or is NULL,
the value of $x is expr2.
28. PHP IF STATEMENTS
if statement - executes some code if one condition is true.
<?php
if (5 > 3) {
echo "Have a good day!";
}
?>
Output - Have a good day!
29. P H P I F. . . E L S E S TAT E M E N T S
The if...else statement executes some code if a condition is true and another code if that condition is
false.
<?php
$t = date("H");
if ($t < "20") {
echo "Have a good day!";
} else {
echo "Have a good night!";
}
?>
Output - Have a good day!
30. I F. . . E LS E I F. . . E LS E S TAT E ME NT
The if...elseif...else statement executes different codes for more than two conditions.
<?php
if ($t < "10") {
echo "Have a good morning!";
} elseif ($t < "20") {
echo "Have a good day!";
} else {
echo "Have a good night!";
}
?>
Output - Have a good day!
![P H P A R R A Y
• An array stores multiple values in one single variable.
• In the following example $cars is an array.The PHP var_dump() function returns the data type
and value:
<?php
$cars = array("BMW","Toyota");
var_dump($cars);
?>
Output –
array(2) { [0]=> string(3) "BMW" [1]=> string(6) "Toyota" }](https://image.slidesharecdn.com/phpppt-250410173810-96aa735c/85/PHP-PPT-pptxPHP-PPT-pptxPHP-PPT-pptxPHP-n-15-320.jpg)
![<?php
$a="first step";
$b="2";
$c="true";
$d="3.89";
$f="null";
$a= (string) $a;
$b= (array) $b;
$c= (bool) $c;
$d= (float) $d;
$f= (string) $f;
//To verify the type of any object in PHP, use
the var_dump() funtion:
var_du($a);
echo"<br>";
var_dump($b);
echo"<br>";
var_dump($c);
echo"<br>";
var_dump($d);
echo"<br>";
var_dump($f);
?>
OUTPUT :
string(10) "first step"
array(1) { [0]=> string(1) "2" }
bool(true)
float(3.89)
string(4) "null"](https://image.slidesharecdn.com/phpppt-250410173810-96aa735c/85/PHP-PPT-pptxPHP-PPT-pptxPHP-PPT-pptxPHP-n-17-320.jpg)
