Web Programming Step by Step, 2nd Edition

Lecture 6: Intro to PHP

Reading: 5.1 - 5.2

Except where otherwise noted, the contents of this document are Copyright 2012 Marty Stepp, Jessica Miller, and Victoria Kirst. All rights reserved. Any redistribution, reproduction, transmission, or storage of part or all of the contents in any form is prohibited without the author's expressed written permission.

Valid HTML5 Valid CSS

5.1: Server-Side Basics

URLs and web servers

http://server/path/file

Server-Side web programming

php jsp ruby on rails asp.net

What is PHP?

PHP logo

Lifecycle of a PHP web request

PHP server

Why PHP?

There are many other options for server-side languages: Ruby on Rails, JSP, ASP.NET, etc. Why choose PHP?

Hello, World!

The following contents could go into a file hello.php:

<?php
print "Hello, world!";
?>
Hello, world!

Viewing PHP output

PHP local output PHP server output

5.2: PHP Basic Syntax

Console output: print

print "text";
print "Hello, World!\n";
print "Escape \"chars\" are the SAME as in Java!\n";

print "You can have
line breaks in a string.";

print 'A string can use "single-quotes".  It\'s cool!';
Hello, World! Escape "chars" are the SAME as in Java! You can have line breaks in a string. A string can use "single-quotes". It's cool!

Arithmetic operators

Variables

$name = expression;
$user_name = "PinkHeartLuvr78";
$age = 16;
$drinking_age = $age + 5;
$this_class_rocks = TRUE;

Types

Comments

# single-line comment

// single-line comment

/*
multi-line comment
*/

for loop

for (initialization; condition; update) {
	statements;
}
for ($i = 0; $i < 10; $i++) {
	print "$i squared is " . $i * $i . ".\n";
}

if/else statement

if (condition) {
	statements;
} else if (condition) {
	statements;
} else {
	statements;
}

while loop (same as Java)

while (condition) {
	statements;
}
do {
	statements;
} while (condition);