PHP Overview CS 3520 1 PHP PHP PHP

  • Slides: 20
Download presentation
PHP Overview CS 3520 1

PHP Overview CS 3520 1

PHP • PHP = PHP: Hypertext Preprocessor • Server-side scripting language that may be

PHP • PHP = PHP: Hypertext Preprocessor • Server-side scripting language that may be embedded into HTML • One goal is to get PHP files to generate client-side code • end up with HTML, CSS, Java. Script, other client-side code! 2

PHP --- and its output PHP <html> <head> <title> PHP Introduction </title> </head> <body>

PHP --- and its output PHP <html> <head> <title> PHP Introduction </title> </head> <body> This is HTML! <? php echo 'This is PHP! '; ? > </body> </html> Output <html> <head> <title> PHP Introduction </title> </head> <body> This is HTML! This is PHP! </body> </html> 3

More PHP <html> <head> <title> PHP Introduction </title> </head> <body> This is HTML! <?

More PHP <html> <head> <title> PHP Introduction </title> </head> <body> This is HTML! <? php echo 'This is PHP! '; // prints to screen /* Here's a longer comment that spans multiple lines. */ ? > </body> </html> PHP tags: <? php and ? > The echo command single line comment ( // ) Multiple line comment (/* and */) 4

PHP file names and code • End in php file extension (order. php, login.

PHP file names and code • End in php file extension (order. php, login. php …. . ) • You start all PHP scripts with the <? php open tag and end the tag after your code with ? >. 5

Variables • PHP is a loosely-typed language • Do not need to declare the

Variables • PHP is a loosely-typed language • Do not need to declare the type of a variable • Type can change throughout the program • Must start with a letter, can contain numbers, no blank spaces • scope (unless defined as global) is the script block it appears inside of. $x = 42; // store the value 42 in $x echo $x; // prints 42 echo $x+1; // prints 43, value of $x is still 42 $x = ‘hello!’ // type of $x can change 6

Longer example 7

Longer example 7

Output previous example Try it 47 Some html goes here. . $jake has the

Output previous example Try it 47 Some html goes here. . $jake has the value 4. This is more HTML. My URL is: : http: //csweb 01. csueastbay. edu/~grew e/CS 3520/PHP/phpvariables. php Your browser is: Mozilla/5. 0 (Windows NT 6. 3; WOW 64) Apple. Web. Kit/537. 36 (KHTML, like Gecko) Chrome/42. 0. 2311. 90 Safari/537. 36 Your IP address is: 108. 243. 32. 249 8

Constants • Constants can be simply defined as follows <? php // Works as

Constants • Constants can be simply defined as follows <? php // Works as of PHP 5. 3. 0 const CONSTANT = 'Hello World'; echo CONSTANT; ? > 9

Some Pre-defined variables--see PHP documentation • There a number of pre-defined variables in PHP.

Some Pre-defined variables--see PHP documentation • There a number of pre-defined variables in PHP. See http: //php. net for a complete listing. Below is a subset of predefined variables/arrays : (http: //php. net/manual/en/reserved. variables. php ) • $GLOBALS • $_SERVER • $_GET • $_POST • $_FILES • $_COOKIE • $_SESSION • $_REQUEST • $_ENV 10

Arrays • 2 kinds • Indexed are numerically indexed starting from 0. • Associative

Arrays • 2 kinds • Indexed are numerically indexed starting from 0. • Associative arrays associate keys to their values and are indexed by their keys. • The following are examples of two associative arrays, $a, $b defined followed by a numerically index array, $c. $a = array("a" => "apple", "b" => "banana"); $b = array("a" => "pear", "b" => "strawberry", "c" => "cherry"); $c = array("apple", "banana"); $a['b']; //will have the value banana $c[1]; //will have the value of banana 11

Operations – similar to C++, Java • Arithmetic operators • +, -, *, /,

Operations – similar to C++, Java • Arithmetic operators • +, -, *, /, % (modulus – remainder after division) • Logical AND (&&), OR (||), NOT (!) • Assignment operators • Shorthand for assignment operators: • $x += $y equivalent to $x = $x + $y • Also works with subtraction, multiplication, division, modulus, and string concatenation 12

Equality: == OR === • Two “equality” operators • == tests for “equality” in

Equality: == OR === • Two “equality” operators • == tests for “equality” in value but not necessarily type • === tests for “identity” in value AND type • == ignores the distinction between: • Integers, floating point numbers, and strings containing the same numerical value • Nonzero numbers and boolean TRUE • Zero and boolean FALSE • Empty string, the string ‘ 0’ and boolean FALSE • Any other non-empty string and boolean TRUE 13

Strings and operations • Concatenation of strings – the. operator $a = ‘hello’; $b

Strings and operations • Concatenation of strings – the. operator $a = ‘hello’; $b = ‘world’; echo $a. ‘ ‘. $b. ‘!’; // prints ‘hello world!’ • String functions • Length: strlen() • Position of substring: strpos() • More on string functions: http: //www. w 3 schools. com/php_ref_string. asp 14

Functions • keyword funciton. • no return type for a function • parameters are

Functions • keyword funciton. • no return type for a function • parameters are defined without type • In the first generic example, you see a function (my. Function) defined with n arguments and the last line of code returns a value. • You would simply call this function via: $the_value = my. Function($a 1, $a 2, . . . $an); • Defining the funciton <? php function my. Function($arg_1, $arg_2, /*. . . , */ $arg_n) { echo "Example function. n"; return $retval; } ? > 15

Function with array as a parameter <? php function takes_array($input) { echo "$input[0] +

Function with array as a parameter <? php function takes_array($input) { echo "$input[0] + $input[1] = ", $input[0]+$input[1]; }? > 16

Functions and arguments • DEFAULT – pass by value 17

Functions and arguments • DEFAULT – pass by value 17

Functions and passing by reference • by default arguments are passed by value to

Functions and passing by reference • by default arguments are passed by value to a function. The following code illustrates how to pass by reference: <? php function add_some_extra(&$string) { $string. = 'and something extra. '; } //how to call the function above $str = 'This is a string, '; add_some_extra($str); echo $str; // outputs 'This is a string, and something extra. ' ? > 18

Functions with default parameter values <? php function doit($type = "txt") { return "Default

Functions with default parameter values <? php function doit($type = "txt") { return "Default type is $type. n"; } //now lets use the function echo doit(); echo doit(null); echo doit("jpg"); ? > 19

More to learn…. • On our website we have a number of Ph. P

More to learn…. • On our website we have a number of Ph. P examples and even have a shopping cart example –go there and read them. • There is much more to learn about Ph. P but, this is enough for our to do our Project and gives you some exposure to server side code using PHP. • Other lectures on our website for PHP cover: form processing, database and more… 20

Overview Overview Overview Overview Overview Overview Overview RockOverview Overview Overview Overview Overview Overview Overview Rock
index php input php regist php logincheck phpindex php input php regist php logincheck php
PHP Intro PHP Webintegrator PHP Baggrund PHP erPHP Intro PHP Webintegrator PHP Baggrund PHP er
PHP AVAudio Visual PHP PHP 20110910 yoya PHPPHP AVAudio Visual PHP PHP 20110910 yoya PHP
php PHP 4 Internals php Andi Gutmans PHPphp PHP 4 Internals php Andi Gutmans PHP
PHP Apa itu PHP PHP singkatan dari PHPPHP Apa itu PHP PHP singkatan dari PHP
Pemrogaman Web PHP PHP PHP akronim dari PHPPemrogaman Web PHP PHP PHP akronim dari PHP
Introduction to PHP HTML HTML PHP PHP phpIntroduction to PHP HTML HTML PHP PHP php
index php input php regist php logincheck phpindex php input php regist php logincheck php
PHP and Classes CS 3520 Classes and ObjectsPHP and Classes CS 3520 Classes and Objects
PHP and Form Processing CS 3520 Idea WePHP and Form Processing CS 3520 Idea We
PHP Basics Introduction to PHP a PHP filePHP Basics Introduction to PHP a PHP file
index php top php 9162020 regist php inputindex php top php 9162020 regist php input
DBW PHP DBW 2017 PHP PHP hypertext processorDBW PHP DBW 2017 PHP PHP hypertext processor
Creating PHP Pages Chapter 8 PHP Functions PHPCreating PHP Pages Chapter 8 PHP Functions PHP
PHP Teppo Risnen LIIKEOAMK 2011 PHP n PHPPHP Teppo Risnen LIIKEOAMK 2011 PHP n PHP
Skriptni jezik PHP Uvod v PHP PHP jeSkriptni jezik PHP Uvod v PHP PHP je
PERTEMUAN 1 ELEMEN DASAR PHP DASAR PHP PHPPERTEMUAN 1 ELEMEN DASAR PHP DASAR PHP PHP
PHP What is PHP PHP is an acronymPHP What is PHP PHP is an acronym