PHP - 1h

How it works Client requests document Server loads document in memory Server processes document with relevant module (PHP) Server sends XHTML document to client Client displays document

Hello World!

Output 1 Hello World

Output 2 Hello World

PHP Syntax basics PHP code embedded in Files containing PHP code must have a.php extension (or php3, etc) Syntax very similar to C and Java –Comments as in C/Java: /* comment */ // comment –But also: # comment

PHP Syntax basics Syntax very similar to C and Java –Statements delimited by ; Variables preceded by $, for example: –$x = 2; –$first_name = joe;

Data types Integer – for whole numbers Float – for real numbers String – for strings of characters Boolean – for true or false values Array – For collections of data Object – For OO programming

Strings <?php $first_name = ‘John’; $last_name = ‘Doe’; echo $first_name; ?> Output: John

Strings <?php $first_name = ‘John’; $last_name = ‘Doe’; echo ‘$first_name’; ?> Output: $first_name

Strings <?php $first_name = ‘John’; $last_name = ‘Doe’; echo “$first_name”; ?> Output: John

Strings <?php $first_name = ‘John’; $last_name = ‘Doe’; echo "You said: \"my name is $first_name $last_name\"";?> Output: You said: “my name is John Doe”

Strings <?php $first_name = ‘John’; $last_name = ‘Doe’; echo $first_name{0}; ?> Output: J

Strings <?php $first_name = ‘John’; $last_name = ‘Doe’; echo substr('abcdef', 1, 4); ?> Output: bcde

Strings <?php $first_name = ‘John’; $last_name = ‘Doe’; echo substr($first_name, 0, 6); ?> Output: ??? you tell me!!

Integers and Floats <?php $a = 1234; $b = 12.02; ?> Integer type: Float type:

Boolean Logical operators: –And: && –Or: ¦¦ –Not: ! Boolean type:

Array idFirst NameLast NameJob 1JoeSmithSurgeon 2JohnJohnsonNurse 3JackJacksonConsultant 4JimJonesIT

Numerically indexed array <?php $names = array(‘Joe’, ‘John’, ‘Jack’, ‘Jim’ ); echo $names[1]; ?> Output: John

if, else, elseif <?php $value = 24; if ($value < 20) echo “not enough!”; elseif ($value < 30) echo “reasonable.”; elseif ($value < 40) echo “ok!”; else echo “Too much!”; ?>

switch <?php switch ($value){ case 24: echo "Correct!"; break; case 25: echo "Almost correct!"; break; default: echo "Too much!"; }?>

for <?php for ( ; ; ) { } ?> ($i = 1$i <= 10 $i++ echo $i; Output:

for <?php for ($i = 1; $i <= 10; $i++) { echo $i; } ?> Output:

foreach <?php $arr = array("one", "two", "three"); echo "Using a for loop: \n"; for ($i = 0; $i < sizeof($arr); $i++) { echo "Value: $arr[$i] \n"; } echo "Using a foreach loop: \n"; foreach ($arr as $value) { echo "Value: $value \n"; } ?>

while <?php $i = 1; while ($i <= 10) { echo $i i++; } Output: