PHP - Introduction Week 5 Dr. Ken Cosh Introducing PHP 1

Introduction PHP : Hypertext Preprocessor Server-side script language Supported by Apache/IIS on various platform (MS/Linux/Mac OS) Opensource (PHP License v3.01) 2

Introduction – cont. Extension:.php File content Html code PHP code 3 HTML

Installation LAMP (or MAMP, or WAMP…) Testing Create a file and named it “test.php” The content is “ ” 4

Outline PHP Structure Comments, Syntax, Variables Operators Conditionals Looping 5

Basic Syntax Script blockings start with Can be anywhere in the code It can be Inside the block are html-code, php-code, or text Comment the code by // or /* */ as in C 6

Basic Syntax Put the script in test.php <?php echo “hello, world”; ?> 7

Variables One type, just variables Can store numbers, strings, or array Conversion between type is automatically done. Variables begin with $, e.g. $var1 = 1; or $var2 = “alice”; No declaration is required. 8

Variables Naming rules Begins with letter or _ (after $) Contains only A-Z, a-z, 0-9, and _ 9

Variables - Array 10  Numeric  $cars=array("Saab","Volvo","BMW","Toyota");  $cars[0]="Saab";  $cars[1]="Volvo";  $cars[2]="BMW";  $cars[3]="Toyota";

Variables - Array 11  Associative  $ages = array("Peter"=>32, "Quagmire"=>30, "Joe"=>34);  Or  $ages['Peter'] = "32";  $ages['Quagmire'] = "30";  $ages['Joe'] = "34";  Example, <?php $ages['Peter'] = "32"; $ages['Quagmire'] = "30"; $ages['Joe'] = "34"; echo "Peter is ". $ages['Peter']. " years old."; ?>

Strings Functions Concatenate:. Length: strlen() Search/Position: strpos(text, pattern) More information:

Strings Put the script in test2.php <?php $h1 = “hello”; $h2 = “world”; echo $h1.”, “.$h2.” ”; echo “h1 has: “.strlen($h1).” letters in it ”; ?> 13

Operators - Arithmetic 14

Operators - Assignment 15

Operators - Comparison 16

Operators - Logical 17

Control Flow if/while/do…while/for All the same as C. for each Syntax foreach ($array as $value) { code to be executed; } 18

Control Flow Example <?php $x=array("one","two","three"); foreach ($x as $value) { echo $value. " "; } ?> 19

Form Put the script in test_form.php Name: Age: 20

Form Put the script in welcome.php Welcome ! You are years old. 21

Form Get, put the script in test_form.php Name: Age: 22

Form Get Visibility Though, it can be bookmarked Not suitable for large variables (>2000 characters) 23