0_CodeSchool-TryPHP

(1)

(2)

Getting Started

The Basics of PHP

(3)

Here’s what we’ll go over in this course.

What Will This Course Cover?

Level 1

Level 2

Level 3

Level 4

Syntax Basics & Variables

Simple Arrays & Associative Arrays

Operators & Comparison Statements

Looping Constructs

(4)

Suggested prerequisites:

What Do You Need to Know?

Basic HTML & CSS

(5)

Why PHP, Why Now?

PHP is a server-side scripting language that has been around since 1997 and has grown into a modern and

performant tool for building websites and applications.

Let’s get started!

Request and response processing with forms

High performance, scales easily

Allows execution of code inline with our HTML markup

Simple reading and processing of ﬁles and images

(6)

<!DOCTYPE html>

<html>

<head>

</head>

<body>

Hello World

</body>

</html>

index.html _HTML

Starting From Scratch

Hello World

Output

(7)

index.php _PHP

Renaming Our File

Hello World

<!DOCTYPE html>

<html>

<head>

</head>

<body>

Hello World

</body>

</html>

Output

Let’s change the ﬁle from .html to .php so it can be processed by the server.

(8)

What Is Diﬀerent Now?

processing validation

rendering

Web Browser Web Server

Request URL

Receive HTML & assets

Look for any PHP code

Execute code

(9)

<!DOCTYPE html>

<html>

<head>

</head>

<body>

<?php

Creating a Code Block

Output

PHP code is written

between these symbols

Let’s write some code that will output something so we can see it here!

</body>

</html>

?>

(10)

<!DOCTYPE html>

<html>

<head>

</head>

<body>

<?php

Our First PHP Code

Hello World

Output

echo outputs whatever comes after it PHP statements end in semicolons

?>

</body>

</html>

(11)

<!DOCTYPE html>

<html>

<head>

</head>

<body>

<?php

Variables and Data Subject to Change

Output

Variables in PHP always start with a $

Notice that the data in the variable isn’t printed out automatically

?>

</body>

</html>

(12)

<!DOCTYPE html>

<html>

<head>

</head>

<body>

<?php

Outputting Data That’s Stored in Variables

Hoba

Output

Echoing the variable outputs the data inside of it

?>

</body>

</html>

$name

=

'Hoba'

;

echo

$name

;

(13)

Variable Naming Conventions

Variables must always begin with a $ followed by a letter.

$10_best_targets

$name

$_age

$full_name

$war_1984

$so-very-invalid

stalemate

(14)

<?php $name

=

'Hoba'

;

?>

<!DOCTYPE html>

<html>

<head>

<title>

PHP Code Can Go Anywhere

Hoba

Output

Assign the variable

Use the variable

</title>

</head>

<body>

<?php

echo

$name

;

?>

</body>

</html>

(15)

<?php $name

=

'Hoba'

;

?>

<!DOCTYPE html>

<html>

<head>

<title>

Variables Can Be Used in Multiple Locations

Hoba

Output

Same variable used twice

</title>

</head>

<body>

<?php

echo

$name

;

?>

</body>

</html>

<?php

echo

$name

;

?>

(16)

Let’s have a quick review.

What Have We Learned?

•

Syntax basics

•

Code blocks

•

PHP request and response server workﬂow

•

Variables and naming rules

•

The echo statement

(17)

(18)

Strings & Data

Level 1

(19)

<?php $name

=

'Hoba'

;

?>

<!DOCTYPE html>

<html>

<head>

<title><?php

echo

$name

;

?></title>

</head>

<body>

<?php

echo

Our Code So Far

</body>

</html>

;

?>

$name

(20)

<?php $name

=

'Hoba'

;

?>

<!DOCTYPE html>

<html>

<head>

<title><?php

echo

$name

;

?></title>

</head>

<body>

<?php

echo

Combining More Data With Variables

Meteor Name: Hoba

Output

Notice the space?

The dot means “combine these two things”

</body>

</html>

;

?>

$name

Meteor Name:

'

.

(21)

<?php $name

=

'Hoba'

;

?>

<!DOCTYPE html>

<html>

<head>

<title><?php

echo

$name

;

?></title>

</head>

<body>

<?php

echo

String Evaluation

Meteor Name: Hoba

Output

Variables will print inside strings as long as you wrap them in

double quotes

$name

Meteor Name:

"

;

?>

"

</body>

</html>

(22)

PHP Data Types: Strings

<?php

$size

=

'epic'

;

$weight

=

'600 Million Grams'

;

To deﬁne a string, we will surround our information in single quotes during assignment.

(23)

PHP Data Types: Integers

<?php

$discovered

=

1920

;

$speed

=

720 ;

(24)

Floating point numbers will be any number that decimal point can “ﬂoat.”

PHP Data Types: Floats

<?php

$width

=

8.9 ;

(25)

Boolean is a data type that can contain one of two values: a true or a false.

PHP Data Types: Booleans

<?php

$largest

=

true

;

(26)

<body>

PHP Data Types: The Results

Output

<?php

echo

"

$size

"

;

echo

"

$weight

"

;

echo

"

$discovered

"

;

echo

"

$speed

"

;

echo

"

$width

"

;

echo

"

$latitude

"

;

</body>

…

epic

600 Million Grams

1920

720

8.9 -19.5833333333

If you echo a false boolean, nothing will appear

?>

</body>

echo

"

$largest

"

;

echo

"

$destroyed

"

;

(27)

What Have We Learned?

•

String concatenation

•

Strings

•

Integers

•

Floating point numbers or ﬂoats

•

Booleans

(28)

(29)

Arrays

Simple & Associative Arrays

(30)

<?php

// We could keep going with variables

$meteor_1

=

'Hoba'

;

$meteor_2

=

'Cape York'

;

$meteor_3

=

'Campo del Cielo'

;

$meteor_4

=

'Canyon Diablo'

;

…

$meteor_42

=

'Prefect'

;

index.php

Why an Array?

(31)

Arrays, a Map

An array maps values to keys, like an address for setting and recalling.

Key Value

0 Hoba

1 Cape York

2 Campo del Cielo

(32)

<?php

// Create our array, using the php array function

$meteors

=

array

();

// Create our array, using a shortcut available since 5.4

$meteors

=

[];

index.php

Creating an Array

Here, the brackets deﬁne an empty array

The array function has good readability Let’s create an empty array to hold our meteorite data.

(33)

<?php

index.php

Array With Values

Array

Output

echo will not show the data within the array

We can create an array with one or more key value pairs using the same function.

// Echo the array

echo

(

$meteors

);

// Create our array with a single value

$meteors

=

array

(

'Hoba'

);

$meteors

=

[

'Hoba'

];

// Create array with multiple values

(34)

<?php

index.php

Array With Values

Array (

[0] => Hoba

[1] => Cape York

)

Output

print_r will echo human-readable output

We can create an array with one or more key value pairs using the same function.

// Let's take a look at our array

with an internal function

print_r

(

$meteors

);

// Create our array with a single value

$meteors

=

array

(

'Hoba'

);

$meteors

=

[

'Hoba'

];

// Create array with multiple values

(35)

<?php

index.php

Adding More Data to Our Array

Empty brackets after the variable name indicate a new item in the array

Array (

[0] => Hoba

[1] => Cape York

[2] => Campo del Cielo

[3] => Canyon Diablo

)

Output

We can append new values by placing square brackets after the array variable.

// Let's add two more items

$meteors

[]

=

'Campo del Cielo'

;

$meteors

[]

=

'Canyon Diablo'

;

print_r

(

$meteors

);

…

(36)

<?php

index.php

How Can We Access This Data?

Remember: Array keys are 0 indexed

Hoba

Output

Placing the key, or index, inside the square bracket gives us access to the value.

$meteors

=

array

(

'Hoba'

,

'Cape York'

,

'Campo del Cielo'

,

'Canyon Diablo'

);

(37)

<?php

index.php

How Can We Access This Data?

Hoba

Cape York

Canyon Diablo

Output

Placing the key, or index, inside the square bracket gives us access to the value.

echo

$meteors

[1];

echo

$meteors

[3];

$meteors

=

array

(

'Hoba'

,

'Cape York'

,

'Campo del Cielo'

,

'Canyon Diablo'

);

(38)

<?php

index.php

Modifying an Existing Item

Choose your key to modify

Array (

[0] => Los Angeles

[1] => Cape York

[2] => Campo del Cielo

[3] => Canyon Diablo

)

Output

Then modify the value

Placing the key inside also allows us access to modify the value.

$meteors

[0] =

'Los Angeles'

;

print_r

(

$meteors

);

…

(39)

Storing Even More Data in an Array

What if we want to store more information about the meteorite?

Name Weight Location Year

Hoba 600000000 -19.58333, 17.91667 1920

Cape York 58200000 76.13333, -64.93333 1818

Campo del Cielo 50000000 -27.46667, -60.58333 1576

(40)

<?php

index.php

Associative vs. Index Arrays

Array (

[Hoba] => 600000000

[Cape York] =>

58200000

)

Output

This array operator associates keys with values

The name is our key

Associative arrays allow us to use strings as the key.

$meteors

=

array

(

);

'Hoba'

=>

600000000

,

'Cape York'

=>

58200000

,

print_r

(

$meteors

);

(41)

<?php

index.php

Accessing an Item in the Array

600000000

58020000

Output

Instead of the numerical index, we now use the string key for access.

// Access our data.

echo

$meteors

[

'Hoba'

];

(42)

<?php

index.php

Appending a New Item

Array(

…

[Canyon Diablo]

=> 30000000

)

Output

Place the key inside of square brackets

Then set your value

Using a string key, we can add a new item as well.

// Add new meteorite data.

$meteors

[

'Canyon Diablo'

] =

30000000

;

(43)

What Have We Learned?

•

Numerical indexed arrays

•

Associative arrays

•

Array creation with values

•

Modiﬁcation of array data

(44)

(45)

Arrays

Multidimensional Arrays & Array Functions

(46)

<?php

$games

=

array

(

'sorry'

,

'blackjack'

,

'poker'

,

'life'

,

'scrabble'

,

);

index.php

An Array of Games

sorry

life

scrabble

poker

blackjack

(47)

How can we better organize our list of games?

Groups of Games

sorry

life

scrabble

poker

blackjack

(48)

Splitting our games into two groups can help us sort and recall the data.

Imagining Two Groups

sorry

life

scrabble

poker

blackjack

(49)

<?php

$games

=

array

(

'tabletop'

=>

index.php

Another Dimension

sorry

Tabletop Games

);

'sorry'

(50)

<?php

$games

=

array

(

'tabletop'

=>

index.php

Another Dimension

Tabletop Games

);

array

(

)

(51)

Scrabble

Life

<?php

$games

=

array

(

'tabletop'

=>

index.php

Another Dimension

Tabletop Games

);

)

,

'sorry'

,

'life'

,

'scrabble'

,

array

(

Sorry

(52)

<?php

$games

=

array

(

'tabletop'

=>

index.php

Another Dimension

Blackjack

Poker

Card Games

'sorry'

,

'life'

,

'scrabble'

,

array

(

)

,

'card'

=>

array

(

'poker'

,

'blackjack'

,

);

),

Tabletop Games

Scrabble

Life

Sorry

(53)

Array(

[tabletop] => Array(

[0] => sorry

[1] => life

[2] => scrabble

[card] => Array(

[0] => poker

[1] => blackjack

)

Output

<?php

Array Inspection

If we print_r our $games array, you can see the multidimensional structure.

);

(54)

<?php

index.php

Accessing Data

Array (

[0] => sorry

[1] => life

[2] => scrabble

)

Output By using the array’s key, we can see the array value.

);

[

'tabletop'

]

(55)

<?php

index.php

Accessing Data

Array (

[0] => poker

[1] => blackjack

)

Output By using the array’s key, we can see the array value.

);

[

'tabletop'

]

print_r

(

$games

(56)

<?php

index.php

Accessing Data

sorry

Output

By using the array’s key, we can see the array value.

);

[

'tabletop'

]

print_r

(

$games

print_r

(

$games

[

'card'

]);

(57)

<?php

index.php

Modifying the Data

Array (

[0] => rummy

[1] => blackjack

)

Output

Instead of single item access, we can use the same methods to change a value.

print_r

(

$games

[

'card'

]);

(58)

<?php

$people

=

array

(

index.php

Array Functions: count

This function lets us count all the items in an array.

4

Output

echo

count

(

$people

);

'David'

,

'Jennifer'

,

'Falken'

,

'Joshua'

);

,

(59)

<?php

$people

=

array

(

index.php

Array Functions: implode

'David Jennifer

Falken Joshua'

Output

implode joins all elements of the array into a string.

echo

implode

(

' '

,

$people

);

'David'

,

'Jennifer'

,

'Falken'

,

'Joshua'

);

,

the character that separates the combined array values

(60)

<?php

$people

=

array

(

index.php

Array Functions: shuﬄe

'Jennifer David

Joshua Falken'

Output

shuﬄe changes the array in place to a random order.

echo

implode

(

' '

,

$people

);

// Randomize the array.

shuffle

(

$people

);

'David'

,

'Jennifer'

,

'Falken'

,

'Joshua'

);

,

(61)

<?php

$people

=

array

(

index.php

Array Functions: asort

asort will sort the array values, in place, in alphabetical order.

'David Falken

Jennifer Joshua'

Output

echo

implode

(

' '

,

$people

);

// Sort the array alphabetically.

asort

(

$people

);

(62)

What Have We Learned?

•

Multidimensional array basics

•

Some simple array functions

•

shuﬄe

•

implode

•

asort

•

count

(63)

(64)

Conditionals & Operators

What If? Now What? What Else?

(65)

php >

Arithmetic Operators

These are some of the arithmetic operators available to us in PHP.

5 + 5

10 5 - 2

3 5 * 2

10 2 / 5

0.4 5 ** 2

25

Addition Multiplication Subtraction

(66)

php >

Comparison Operators

These are some of the comparison operators available to us in PHP.

5 == '5'

true

5 > 2

true

5 ==='5'

false

5 != 2

true

2 < 5

true

5 >= 5

true

Equal Identical

Greater Than Less Than

(67)

php >

5 ==='5'

false

Identical Comparison Operator

Identical

5 // is integer data

'5'

// is string data

(68)

<?php

$year

=

2016

;

if

(

$year

>=

2001

) {

echo

"Hal can’t do that for you, and he is sorry."

;

index.php

Control Flow

Test if our $year is greater than or equal to 2001

Run code within as long as our Test is true The if statement allows us to execute code based on a condition.

(69)

<?php

$year

=

2016

;

if

(

$year

>=

2001

) {

echo

"Hal can’t do that for you, and he is sorry."

;

index.php

Default Condition

Run this code if our Test is false The else statement allows us to run code when the if returns false.

}

else

{

echo

"You still have time. Destroy the machines!"

;

}

(70)

php >

$a || $b

true

<?php

$a

=

true

;

$b

=

false

;

Logical Operators

These are some of the logical operators available to us in PHP.

$a && $b

false

!$b

true

And Or Not

True if $a and $b are both true True if either $a or $b are true True if only the variable is not true

(71)

<?php

$year

=

1984

;

index.php

Testing Multiple Conditions

Is $year between 1994 and 2000?

Using the logical operator and, we can test to see if multiple conditions are true.

if

(

$year

>=

1994

&&

$year

<

2001

){

echo

"Skynet is growing stronger every day."

;

}

else

{

echo

"You still have time. Destroy the machines!"

;

}

(72)

<?php

$year

=

1984

;

index.php

Multiple if Statements

Test this if the ﬁrst condition is false

The elseif statement allows us to have multiple conditions.

if

(

$year

>=

2001

) {

echo

"Hal can’t do that for you, and he is sorry."

;

}

elseif

(

$year

>=

1984

) {

echo

"Eurasia has fallen! Rejoice with Big Brother."

;

}

else

{

echo

"You still have time. Destroy the machines!"

;

}

(73)

What Have We Learned?

•

Comparison operators

•

Arithmetic operators

•

if, if-else, else comparisons

•

Logical operators

(74)

(75)

Loops

Cycle Through All the Data

(76)

Don’t Repeat Yourself

<?php

$value

=

1 *

12 ;

echo

"1 times 12 is

$value

"

;

$value

=

2 *

12 ;

echo

"2 times 12 is

$value

"

;

$value

=

3 *

12 ;

echo

"3 times 12 is

$value

"

;

$value

=

4 *

12 ;

echo

"4 times 12 is

$value

"

;

$value

=

5 *

12 ;

echo

"5 times 12 is

$value

"

;

Assign the product of 1 and 12 to a variable. The DRY (or “Don’t Repeat Yourself”) method helps us keep our code eﬃcient.

(77)

<?php

$i

=

1 ;

while

(

$i

<=

12 ) {

$value

=

$i

*

12 ;

echo

"

$i

times 12 is

$value

"

;

$i

++;

}

while Loops

Initialize an integer variable and set it to 1 Now let’s initialize, test, and increment.

(78)

<?php

$i

=

1 ;

while

( $i <=

12 ) {

$value

= $i *

12 ;

echo

"

$i

times 12 is

$value

"

;

$i++;

}

while Loops

Initialize an integer variable and set it to 1

Test if our variable is less than or equal to 12 Now let’s initialize, test, and increment.

(79)

<?php

$i

=

1 ;

while

( $i <=

12 ) {

$value

= $i *

12 ;

echo

"

$i

times 12 is

$value

"

;

$i++;

}

while Loops

Test if our variable is less than or equal to 12

Run code within as long as our Test is true Now let’s initialize, test, and increment.

(80)

<?php

$i

=

1 ;

while

( $i <=

12 ) {

$value

= $i *

12 ;

echo

"

$i

times 12 is

$value

"

;

$i++;

}

while Loops

Increment our test integer $i by one

Run code within as long as our Test is true Now let’s initialize, test, and increment.

(81)

while Loops

<?php

$i

=

1 ;

while

(

$i

<=

12 ) {

$value

=

$i

*

12 ;

echo

"

$i

times 12 is

$value

"

;

$i

++;

}

Output

1 times 12 is 12

2 times 12 is 24

3 times 12 is 36

…

10 times 12 is 120

11 times 12 is 132

12 times 12 is 144

Now let’s initialize, test, and increment.

(82)

<?php

for

(

Using a for Loop

$i++ is the same as $i = $i + 1 Now let’s initialize, test, and increment.

Increment our integer variable $i by one

$i

=

1 ;

$i

<=

12 ;

$i

++

$value

=

$i

*

12 ;

echo

"

$i

times 12 is

$value

"

;

}

(83)

<?php

for

(

Using a for Loop

1 times 12 is 12

2 times 12 is 24

3 times 12 is 36

…

10 times 12 is 120

11 times 12 is 132

12 times 12 is 144

Output

Now let’s initialize, test, and increment.

$i

=

1 ;

$i

<=

12 ;

$i

++) {

$value

=

$i

*

12 ;

echo

"

$i

times 12 is

$value

"

;

}

(84)

<?php

$meteors

=

array

(

The Simple Meteorite Array

How else could we extract each item in the array other than direct access?

'Hoba'

'Cape York'

'Campo del Cielo'

'Canyon Diablo'

,

);

(85)

Looping Access to the Array

<?php

$meteors

=

array

(

On each pass through our foreach loop, the data in

$meteor will update with the next item in the collection. The foreach and as will allow us to cycle through each item in our array.

Hoba

Cape York

Campo del Cielo

Canyon Diablo

The value, our meteorite names

Output

);

,

'Canyon Diablo'

'Campo del Cielo'

'Cape York'

'Hoba'

foreach

(

$meteors

as

$meteor

) {

}

(86)

<?php

$meteors

=

array

(

Associative Meteorite Array

What would happen if we ran this array through our existing foreach loop?

'Hoba'

'Cape York'

'Campo del Cielo'

'Canyon Diablo'

,

);

=>

600000000

=>

58200000

=>

50000000

=>

30000000

(87)

Looping Through an Associative Array

<?php

$meteors

=

array

(

600000000

58200000

50000000

30000000

The value is our meteorite weight!

What would happen if we ran this array through our existing foreach loop?

Output

foreach

(

$meteors

as

$meteor

) {

echo

$meteor

;

}

'Hoba'

'Cape York'

'Canyon Diablo'

'Campo del Cielo'

=>

600000000

=>

58200000

=>

50000000

=>

30000000

,

);

(88)

How Can We Access the Key and Value?

<?php

$meteors

=

array

(

$name and $weight will change values with each pass

We can use the array operator => to set up the key and value variables.

);

'Canyon Diablo'

=>

30000000

,

'Campo del Cielo'

=>

50000000

,

'Cape York'

=>

58200000

,

'Hoba'

=>

600000000

,

foreach

(

$meteors

as

$name

=>

$weight

){

}

(89)

<?php

$meteors

=

array

(

Hoba weighs

600000000 grams.

…

Canyon Diablo weighs

30000000 grams.

We can use the object operator => to set up the key and value variables.

How Can We Access the Key and Value?

Output

);

'Canyon Diablo'

=>

30000000

,

'Campo del Cielo'

=>

50000000

,

'Cape York'

=>

58200000

,

=>

600000000

'Hoba'

,

foreach

(

$meteors

as

$name

=>

$weight

){

}

(90)

A Complete Picture

<?php

$meteors

=

array

(

$epic

=

600000000

;

// 600 million grams

$huge

=

50000000

;

// 50 million grams

);

'Canyon Diablo'

=>

30000000

,

'Campo del Cielo'

=>

50000000

,

'Cape York'

=>

58200000

'Hoba'

=>

600000000

(91)

A Complete Picture

<?php

$meteors

=

array

(

?>

foreach

($meteors

as

$name

=>

$weight)

{

$epic

=

600000000

;

// 600 million grams

$huge

=

50000000

;

// 50 million grams

);

'Canyon Diablo'

=>

30000000

,

'Campo del Cielo'

=>

50000000

,

'Cape York'

=>

58200000

,

'Hoba'

=>

600000000

,

(92)

A Complete Picture

<?php

$meteors

=

array

(

if

($weight >= $epic)

{

echo

'You have found an epic meteorite! '

;

echo

'Your meteorite\'s name is '

.

$name

.

' '

;

}

?>

foreach

($meteors

as

$name

=>

$weight)

{

$epic

=

600000000

;

// 600 million grams

$huge

=

50000000

;

// 50 million grams

);

'Canyon Diablo'

=>

30000000

,

'Campo del Cielo'

=>

50000000

,

'Cape York'

=>

58200000

,

(93)

<?php

$meteors

=

array

(

A Complete Picture

<?php

$meteors

=

array

(

?>

}

elseif

(

$

weight

>=

$huge

)

{

echo

'You have found a huge meteorite! '

;

echo

'Your meteorite\'s name is '

.

$name

.

‘ '

;

}

if

($weight >= $epic)

{

echo

'You have found an epic meteorite! '

;

echo

'Your meteorite\'s name is '

.

$name

.

' '

;

}

foreach

($meteors

as

$name

=>

$weight)

{

$epic

=

600000000

;

// 600 million grams

$huge

=

50000000

;

// 50 million grams

(94)

A Complete Picture

<?php

$meteors

=

array

(

}

elseif

(

$

weight

>=

$huge

)

{

echo

'You have found a huge meteorite! '

;

echo

'Your meteorite\'s name is '

.

$name

.

‘ '

;

if

($weight >= $epic)

{

echo

'You have found an epic meteorite! '

;

echo

'Your meteorite\'s name is '

.

$name

.

' '

;

}

foreach

($meteors

as

$name

=>

$weight)

{

$epic

=

600000000

;

// 600 million grams

$huge

=

50000000

;

// 50 million grams

...);

,

=>

600000000

'Hoba'

}

?>

else

{

echo

'You have found a meteorite, awesome! '

;

(95)

What Have We Learned?

•

while loop

•

for loop

•

foreach loop

•

foreach with key/value

(96)

0_CodeSchool-TryPHP

Getting Started

The Basics of PHP

What Will This Course Cover?

Level 1

Level 2

Level 3

Level 4

Syntax Basics & Variables

Simple Arrays & Associative Arrays

Operators & Comparison Statements

Looping Constructs

What Do You Need to Know?

Basic HTML & CSS

Why PHP, Why Now?

Request and response processing with forms

High performance, scales easily

Allows execution of code inline with our HTML markup

Simple reading and processing of ﬁles and images

<!DOCTYPE html>

<html>

<head>

<title></title>

</head>

<body>

<p>Hello World</p>

</body>

</html>

Starting From Scratch

Hello World

Renaming Our File

Hello World

<!DOCTYPE html>

<html>

<head>

<title></title>

</head>

<body>

<p>Hello World</p>

</body>

</html>

What Is Diﬀerent Now?

<!DOCTYPE html>

<html>

<head>

<title></title>

</head>

<body>

<p><?php

Creating a Code Block

</body>

</html>

</p>

?>

<!DOCTYPE html>

<html>

<head>

<title></title>

</head>

<body>

<p><?php

Our First PHP Code

Hello World

?></p>

</body>

</html>

<!DOCTYPE html>

<html>

<head>

<title></title>

</head>

<body>

<p><?php

Variables and Data Subject to Change

?></p>

</body>

</html>

<!DOCTYPE html>

<html>

<head>