php basics
TRANSCRIPT
PHP Basics
Jamshid HashimiTrainer, Cresco Solution
http://www.jamshidhashimi.com [email protected] @jamshidhashimi ajamshidhashimi
Afghanistan Workforce Development Program
AGENDA
• About PHP & MySQL• Advantage of using PHP for Web Development• PHP Installation, PHP Syntax & PHP Variable• PHP Strings• PHP Operators• Conditional Statements– if (...else) Statement– Switch Statements
• Exercise!
PHP: Introduction
• PHP is a programming language for building dynamic, interactive Web sites. As a general rule, PHP programs run on a Web server, and serve Web pages to visitors on request. One of the key features of PHP is that you can embed PHP code within HTML Web pages, making it very easy for you to create dynamic content quickly.
PHP: Introduction
• PHP stands for PHP: Hypertext Preprocessor, which gives you a good idea of its core purpose: to process information and produce hypertext (HTML) as a result.
• PHP is a server-side scripting language, which means that PHP scripts, or programs, usually run on a Web server. (A good example of a client-side scripting language is JavaScript, which commonly runs within a Web browser.)
PHP: The Process
• A visitor requests a Web page by clicking a link, or typing the page’s URL into the browser’s address bar. The visitor might also send data to the Web server at the same time, either using a form embedded in a Web page, or via AJAX (Asynchronous JavaScript And XML).
• The Web server recognizes that the requested URL is a PHP script, and instructs the PHP engine to process and run the script.
• The script runs, and when it’s finished it usually sends an HTML page to the Web browser, which the visitor then sees on their screen.
PHP• PHP: Hypertext Preprocessor• Appeared in: 1995; 18 years ago• Designed by: Rasmus Lerdorf• Developer: The PHP Group• Stable release: 5.4.15 (May 9, 2013; 25 days ago)• Typing discipline: Dynamic, weak• Influenced by: Perl, C, C++, Java, Tcl• Implementation language: C• OS: Cross-platform• License: PHP License• Usual filename extensions .php, .phtml, .php4 .php3, .php5, .phps
Why PHP?
• Easy to learn• Familiarity with syntax• Free of cost• Efficiency in performance• A helpful PHP community• Cross Platform
MySQL• MySQL is the most popular database system used with PHP.• MySQL is a database system used on the web• MySQL is a database system that runs on a server• MySQL is ideal for both small and large applications• MySQL is very fast, reliable, and easy to use• MySQL supports standard SQL• MySQL compiles on a number of platforms• MySQL is free to download and use• MySQL is developed, distributed, and supported by Oracle
Corporation• MySQL is named after co-founder Monty Widenius's daughter: My
PHP Editor + W(M)AMP Installation
PHP Syntax
• Basic PHP Syntax<?php// PHP code goes here?>
<!DOCTYPE html><html><body><h1>My first PHP page</h1><?phpecho "Hello World!";?></body></html>
PHP Variables
• Variables are a fundamental part of any programming language. A variable is simply a container that holds a certain value.
echo 2 + 2;
echo 5 + 6;
echo $x + $y;
PHP Variables
• A variable starts with the $ sign, followed by the name of the variable
• A variable name must begin with a letter or the underscore character
• A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
• A variable name should not contain spaces• Variable names are case sensitive ($y and $Y are
two different variables)
Strings: Examples
Valid examples of strings:
$string1 = "This is a string in double quotes";$str = 'This is a somewhat longer, singly quoted string';$string2 = ""; // a string with zero characters
Strings: Examples
Single quote strings vs. Double quote strings:
$variable = "name";$text = "My $variable will print!";echo $text;> My name will print!$text = 'My $variable will not print!';echo $text;> My $variable will not print!
Strings: Concatenation(.)
• String concatenation is the string manipulation method when you join 2 or more strings together.
$str1 = ”AWD Training";$str2 = "-Cresco Solutions";echo $str1.$str2;> AWD Training-Cresco Solutions
Strings: strlen()
• Returns the length of the string
$str = "Kabul is the capital of Afghanistan";echo strlen($str);> 35
Strings: explode()
• explode — Split a string by string
$str = "This is a somewhat longer, singly quoted string";$new_str = explode(" ",$str);print_r($new_str);>Array ( [0] => This [1] => is [2] => a [3] => somewhat [4] => longer, [5] => singly [6] => quoted [7] => string )
Strings: strpos()
• strpos — Find the position of the first occurrence of a substring in a string
$str = "Kabul is the capital of Afghanistan";$position = strpos($str,"capital");echo $position;> 13
Strings: strtoupper()
• strtoupper — Make a string uppercase
$str = "Kabul is the capital of Afghanistan";echo strtoupper($str);> KABUL IS THE CAPITAL OF AFGHANISTAN
Strings: strtolower()
• strtolower — Make a string lowercase
$str = "Kabul is the capital of Afghanistan";echo strtolower($str);
> kabul is the capital of afghanistan
Strings: ucfirst()
• ucfirst — Make a string's first character uppercase
$str = "afghanistan";echo ucfirst($str);> Afghanistan
Strings: lcfirst()
• lcfirst — Make a string's first character lowercase
$str = "Afghanistan";echo lcfirst($str);> afghanistan
Strings: trim()
• trim — Strip whitespace (or other characters) from the beginning and end of a string
$str = ” Afghanistan is the heart of Asia";var_dump($str);>string(36) “Afghanistan is the heart of Asia"
$str = ” Afghanistan is the heart of Asia";var_dump(trim($str));> string(32) "Afghanistan is the heart of Asia”
Strings: str_replace()
• str_replace — Replace all occurrences of the search string with the replacement string
$str = "Balkh is the capital of Afghanistan";echo str_replace("Balkh","Kabul",$str);> Kabul is the capital of Afghanistan
Strings: substr()
• substr — Return part of a string
$str = "Afghanistan is the heart of Asia";echo substr($str,12);> is the heart of Asia
$str = "Afghanistan is the heart of Asia";echo substr($str,12,12);> is the heart
$str = "Afghanistan is the heart of Asia";echo substr($str,-4);> Asia
Operators
• In all programming languages, operators are used to manipulate or perform operations on variables and values. – PHP Arithmetic Operators– PHP Assignment Operators– PHP Incrementing/Decrementing Operators– PHP Comparison Operators– PHP Logical Operators
Operators: Arithmetic
Operators: Assignment
Operators: Increment & Decrement
Operators: Comparison
Operators: Logical
Conditional Statements
if (condition){ code to be executed if condition is true;}
if (condition){
code to be executed if condition is true;}else{
code to be executed if condition is false;}
Conditional Statements
if (condition){
code to be executed if condition is true;}else if (condition){
code to be executed if condition is true;}else{
code to be executed if condition is false;}
Conditional Statements
switch (n){case label1: code to be executed if n=label1; break;case label2: code to be executed if n=label2; break;default: code to be executed if n is different from both label1 and label2;}
Exercise!
• Write a program called CheckPassFail which prints "PASS" if the int variable "mark" is more than or equal to 50; or prints "FAIL" otherwise.
• Write a program called CheckOddEven which prints "Odd Number" if the int variable “number” is odd, or “Even Number” otherwise.
Exercise!
• Write a program which add, subtract, divide and multiply two number and show the result on the screen.
• Write a program to find the biggest positive number among a,b,c,d numbers
• Write a program which returns the average of given 3 number
Exercise!
• Write a program which categorize people according to their work experience:
0: Fresh Graduate1-3: Mid-Level4-8: Senior Level9-30: Superman• Write a program which outputs the quarter
(Q1,Q2,Q3,Q4) of the year a given date is in. – e.g. 17 June 2013 output must be: Q2 2013
QUESTIONS?