Programming Languages for Beginners: March 2013

PHP - Arithmetic Operations

Addition (+)
Addition is performed with the "+" symbol.
Ex:
$total = 5 + 6;
Here 5 add to 6 and assign to the total variable
Subtract (-)
Subtract is performed with the "-" symbol.
Ex:
$answer = 8 - 6;
Multiplication (*)
Multiplication is performed with the "*" symbol.
Ex:
$answer = 5 * 6;

PHP - Variables and Data types

What is a Variable?

Variables are used to store values into the system's memory. Variables allows to perform set of actions and can be re-use within the code. You can change the out put of the program by changing the variable values rather changing the script.

Data Types

String : used for character values such as sentences, names stc

Integer : used to store numeric values of whole numbers

Float : used to store numeric values of real numbers

Boolean: used to store either true or false or 1 or 0

Object : used to store collection of values (data) or methods

Important: PHP is loosely typed language, that means your script determines the data type of the variable.

Ex:

$val = "PHP Programming" // This is considering as String Value

$val = 50 // This is considering as Integer Value

$val = "100" //This is considering as String value

$val = $val * 5 // This is considering as Integer value

$val = $val * 1.25 //This is considering as float value

PHP - Embeded HTML

This post desribe about the PHP scripting, html coding and embedded php scripts.

I'll explain those with an example.

<html>
<head>
    <title>Embedded php</title>
</head>
<body>
    <hr />
    <h3>Embedded php</h3>
    <p>This is a regular HTML paragraph</p>
    <?php
      echo "<p>This is a php paragraph</p>";
    ?>
    <hr />
</body>
</html>

You can see the text inside the php script and out side it. Text inside the php script (comes with echo statement) handled as a script and rest of the text rendered as regular HTML. We can include any no of php blocks inside the html document like java script and any html tag to embedded the code.

Above code displays following output.

Embedded php

This is a regular HTML paragraph
This is a php paragraph.

PHP - Install a Web Server

Wamp Server
This video instruct you how to install wamp server

Xampp server
This video instruct you how to setup xampp server on linux (Fedora)

PHP - My First PHP Program

This is a basic php embeded HTML program.

<?php
echo "<h3>Hello This is my First PHP Program </h3>";
?>

<?php
print ("<h3>Hello This is my First PHP Program </h3>");
?>

According to the above program you can appear Following out put

Hello This is my First PHP Program

echo and print statements are use to write something in the browser. Within the echo statement we can use html tags to format the text.

PHP - Comments

There are 02 comments used with PHP scripts.

Single line Comment
Single line comments can be specified by //
Ex:

<?php
// This script print Hello World in the browser
echo "Hello World"
?>

Multiple line Comment
Multiple Line Comment begins with "/*" and ends with */.
Ex:

<?php
/* This is a multiple line comment You can comment
any no of lines within this block
*/
echo "Hello World"
?>

PHP - How to create php files

Normally PHP script block starts with <?php and ends ?> and it can be embedded with HTML. PHP block can be placed anywhere in the document either with html tags or not.

HTML Embeded php code

<html>

<head>

<title>This is my First PHP Program</title>

</head>

<body>

<?php

echo "This is my First PHP Program";

</body>

</html>

Pure PHP Code

<?php

echo "This is my First PHP Program";

Shorthand PHP Code

Following code executed when the shorthand mood enabled in the server.

<? echo "This is my First PHP Program"; ?>

It is necessary to specify extention of the php file name as ".php" other wise php scrip does not execute.

Ex: Hello.php

PHP

Today onward I'm starting to teach all of you about the server side programming with php. I think these posts are much more interesting for you and hope you enjoy programming with php. Your comments highly appreciate.

Best Wishes,
Priyal

PHP - How to Execute Script

PHP scripts are unable to execute as normal html web pages thus php scripts are run only on the web servers. Therefore before executing the scripts, you should run your web server. All the php pages should be located inside the web server folder.

Through Wamp Server
Running wamp server and put it online before doing the execution. You can see a folder named "www" inside the wamp folder located in your C drive. PHP script pages should be located within that folder. It is better to create a folder and save all the documents there.
PHP files cannot access with its full path like html (Ex: C:/wamp/www/php/hello.php). That www folder act as your local web server stored location and therefore you can call the above path "http://localhost/php/hello.php".
localhost or 127.0.0.1 : this is the dns address of your web server located in your machine.
php : php folder created in www folder.

I think now you are familiar with storing php script pages.

See how to run php files with wamp server

PHP - Introduction

What is PHP?

PHP is stand for PHP Hypertext Preprocessor. PHP is a widely used open source general purpose serverside scripting language for web developing and can be embeded into HTML. PHP originally created by Rasmus Lerdorf and now it is produced by PHP group. Initially it stood as Personal Home Page but now stand for this way. This is an successful free alternative to other web competitors such as Microsoft Asp. Currently php 5.5.0 version released and available from 21st March 2013.

In this note set I'm going to discuss about php and how to execute scripts on your server.

PHP supports many Databases
PHP is an open source Software
PHP is a free Software
PHP is a server side scripting language and executed on the server

Why PHP
PHP is open source solution and runs on every platform such as Windows, Linux, Unix and etc. and compatible with all web servers such as Apache, IIS & Etc

Before you start PHP programming needed to install php in your machine. It is better to download wampserver for windows and xamp server for linux. This includes Apache, php, Mysql and other technologies required for web programming.
Links for Downloads

HTML Drop Down List

Select tag
This tag defines a drop down list to select chices
Syntax:
<select>
<option>Choice 1</option>
<option>Choice 2 </option>
</select>

Option tag uses to define the choices of the list. This should be within the select tag.

Ex:

Code:
<form>
   Designation:
<select>
       <option>Mr. </option>
       <option>Mrs. </option>
       <option>Ms. </option>
       <option>Dr. </option>
       <option>Rev. </option>
       <option>Prof. </option>       <option>Other. </option></select>

Output :
Designation:

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