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PHP - Introduction. Week 5 Dr. Ken Cosh Introducing PHP. Introduction. PHP : Hypertext Preprocessor Server-side script language Supported by Apache/IIS on various platform (MS/Linux/Mac OS) Opensource (PHP License v3.01). Introduction – cont. Extension: .php File content Html code
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PHP - Introduction Week 5 Dr. Ken Cosh Introducing PHP
Introduction • PHP : Hypertext Preprocessor • Server-side script language • Supported by Apache/IIS on various platform (MS/Linux/Mac OS) • Opensource (PHP License v3.01)
Introduction – cont. • Extension: .php • File content • Html code • PHP code Request PHP HTML
Installation • LAMP (or MAMP, or WAMP…) • Testing • Create a file and named it “test.php” • The content is “<$phpphpinfo(); $>”
5 Outline • PHP Structure • Comments, Syntax, Variables • Operators • Conditionals • Looping
6 Basic Syntax • Script blockings start with <?php ?> • 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
7 Basic Syntax • Put the script in test.php <html> <body> <?php echo “hello, world”; ?> </body> </html>
8 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.
9 Variables • Naming rules • Begins with letter or _ (after $) • Contains only A-Z, a-z, 0-9, and _
10 Variables - Array • Numeric • $cars=array("Saab","Volvo","BMW","Toyota"); • $cars[0]="Saab"; • $cars[1]="Volvo"; • $cars[2]="BMW"; • $cars[3]="Toyota";
11 Variables - Array • 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."; ?>
12 Strings • Functions • Concatenate: . • Length: strlen() • Search/Position: strpos(text, pattern) • More information: http://www.w3schools.com/php/php_ref_string.asp
13 Strings • Put the script in test2.php <html> <body> <?php $h1 = “hello”; $h2 = “world”; echo $h1.”, “.$h2.”<br/>”; echo “h1 has: “.strlen($h1).” letters in it <br/>”; ?> </body> </html>
14 Operators - Arithmetic
15 Operators - Assignment
16 Operators - Comparison
17 Operators - Logical
18 Control Flow • if/while/do…while/for • All the same as C. • for each • Syntax foreach ($array as $value) { code to be executed; }
19 Control Flow • Example <html> <body> <?php $x=array("one","two","three"); foreach ($x as $value) { echo $value . "<br />"; } ?> </body> </html>
20 Form • Put the script in test_form.php <html> <body> <form action="welcome.php" method="post"> Name: <input type="text" name="fname" /> Age: <input type="text" name="age" /> <input type="submit" /> </form> </body> </html>
21 Form • Put the script in welcome.php <html> <body> Welcome <?php echo $_POST["fname"]; ?>!<br /> You are <?php echo $_POST["age"]; ?> years old. </body> </html>
22 Form • Get, put the script in test_form.php <html> <body> <form action="welcome.php" method=“get"> Name: <input type="text" name="fname" /> Age: <input type="text" name="age" /> <input type="submit" /> </form> </body> </html> • http://localhost?fname=Peter&age=37
23 Form • Get • Visibility • Though, it can be bookmarked • Not suitable for large variables (>2000 characters)
