Basic Php Tutorials

Date() Functions

2008-12-24T11:25:00.001+05:30

Php date function returns a formatted date string. Every call to a date/time function will generate a E_NOTICE, E_STRICT or E_WARNING if the time zone is not valid.

d - The day of the month (01 to 31)
m -Month (01 to 12)
Y - Year (in four digits)

Syntax :

date(format,timestamp)

Example :

echo date("Y M d", time());
echo date("Y-M-d", time());
echo date("Y / M / d", time());

Output today formated date : 2007 Dec 24, 2007-Dec-24 and 2007 / Dec /24

To get the future date, i.e tommrow :

$tomorrow = mktime(0,0,0,date("m"),date("d")+1,date("Y"));
echo "Tomorrow is ".date("Y/m/d", $tomorrow);

Output : Tomorrow is 2007/12/25

To get a date in the past or future dynamically is like this:

//get timestamp for past/future date I want
$pf_time = strtotime("-3 days");
//format the date using the timestamp generated
$pf_date = date("Y-m-d", $pf_time);

gmdate() - Format a GMT/UTC date/time
idate() - Format a local time/date as integer
getdate() - Get date/time information
getlastmod() - Gets time of last page modification
mktime() - Get Unix timestamp for a date
strftime() - Format a local time/date according to locale settings
time() - Return current Unix timestamp

PHP Variables

2006-04-30T13:07:00.002+05:30

Using Php Variables
Php Variables are are used for storing values, such as strings, numbers। Once stored they can be called from anywhere within the script।

Note :Variables can not have spaces and only contain alpha-numeric characters and underscores. $myVar or $my_Var both is correct.

Output of this script is :
Hi Friend

Below is another example :

Output of is :
2 + 2 is 4

PHP Switch Statement

2005-05-10T14:25:00.001+05:30

Php Switch statement is very useful, it works like if/else statement & reduce the complication of numerous conditions in the script.

Syntax :

switch (expression)
{
case 1
code .. //execute code if expression = 1
break;
case 2
code ... //execute code if expression = 2
break;
default:
code...//execute code if expression not matched
}

Example :

<?php

$value = 6;

switch ($value)

{

case 1:

echo "Value 1";

break;

case 2:

echo "Value 2";

break;

case 3:

echo "Value 3";

break;

default:

echo "Value is " . $value . " not matched!";

}

?>

The while Statement

2005-05-09T09:52:00.001+05:30

The while Statement

The while statement is useful, when you want to loop a code until it's conditions are met.

Syntax :while (condition)
code ....


Example :
");}
echo "Value is ". $val .". condition not met!
";
$val++;
}
?>
Output of this code is :

Value is 0. condition not met!
Value is 1. condition not met!
Value is 2. condition not met!
Value is 3. condition not met!
Value is 4. condition not met!
Value is 5. condition not met!
Value is 6. condition not met!
Value is 7. condition not met!
Value is 8. condition not met!
Value is 9. condition not met!
Value is 10. condition met! 

Above code loops until the value is 10.

The do while Statement

2005-05-08T10:39:00.001+05:30

The do/While repeat through the code, until the condition is met.

Syntax :
do
{
code ...
}
while (condition);
Example :

";
}
while ($val<3);>
Output of this code :

Value is  1
Value is  2
Value is  3

Php For Statement

2005-05-07T10:49:00.001+05:30

PHP For statement is used when you want to loop the code for number of times,
until condition is met.

Syntax :
for (initialization; condition; increment)
{
code ...
}

Example :

<?php

for ($val=1; $val<=3; $val++)

{

echo "This is the text.<br />";

}

?>

Output of this Php code is :

This is the text.
This is the text.
This is the text.

Php Functions

2005-05-06T10:59:00.001+05:30

PHP functions are very useful, because once coded, it can be called from anywhere within the script or from outside. Note, code block must start with function word.

Example 1 : Shows how to call function within the php Script.

<?php

function MyFirstEchoFunction()

{

echo "Hi this is the function called! <br />";

echo "And this is text created by function!";

}
MyFirstEchoFunction()

?>

Another way of calling functions is using include()..
Php Include() lets you import any php or text file in your script.

Example 2 : Create a php file somthing like "test.php" and write this code:

test.php code :

<?php

function MyFirstEchoFunction()

{

echo "Hi this is the function called! <br />";

echo "And this is text created by function!";

}
MyFirstEchoFunction()

?>

Now create destination file, something like "call.php"

Call.php code :

<?php

include("test.php"); //This is the target php file
MyFirstEchoFunction() //We just called the function coded in test.php

?>

Isn't this nice? The output of this file is :
Hi this is the function called!
And this is text created by function!

PHP Forms

2005-05-05T11:50:00.001+05:30

This is the fun part! sooner or later, we all want to collect user data. We can build nifty data collector using HTML and PHP GET/POST .

Create a HTML form Something like.. Easier if you do it in HTML editor. and name it "myform.html"

<form name="form1" method="post" action="collect.php">
Name :
<input type="text" name="name">
<br>
Email :
<input type="text" name="email">
<br>
<input type="submit" name="Submit" value="Submit">
</form>

Now Create another file, this time "collect.php"

<?php
echo $_POST["name"] ."<br />";
echo $_POST["email"];
?>

That's it... After collecting user information, you can do whatever you want In "collect.php" , send email.. send data to database, evaluate.. or just flush it.. etc

See the output :

myform.html :

collect.php :

PHP Predefined variables

2005-05-04T12:20:00.001+05:30

PHP provides a large number of predefined variables to any script which it runs. Many of these variables, From version 4.1.0 onward, PHP provides an additional set of predefined arrays containing variables from the web server (if applicable), the environment, and user input. These new arrays are rather special in that they are automatically global--i.e., automatically available in every scope. For this reason, they are often known as "superglobals".

PHP Superglobals

$GLOBALS: Contains a reference to every variable which is currently available within the global scope of the script. The keys of this array are the names of the global variables. $GLOBALS has existed since PHP 3.

$_SERVER: Variables set by the web server or otherwise directly related to the execution environment of the current script. Analogous to the old $HTTP_SERVER_VARS array (which is still available, but deprecated).

$_GET: Variables provided to the script via URL query string. Analogous to the old $HTTP_GET_VARS array (which is still available, but deprecated).

$_POST: Variables provided to the script via HTTP POST. Analogous to the old $HTTP_POST_VARS array (which is still available, but deprecated).

$_COOKIE: Variables provided to the script via HTTP cookies. Analogous to the old $HTTP_COOKIE_VARS array (which is still available, but deprecated).

$_FILES: Variables provided to the script via HTTP post file uploads. Analogous to the old $HTTP_POST_FILES array (which is still available, but deprecated). See POST method uploads for more information.

$_ENV: Variables provided to the script via the environment. Analogous to the old $HTTP_ENV_VARS array (which is still available, but deprecated).

$_REQUEST: Variables provided to the script via the GET, POST, and COOKIE input mechanisms, and which therefore cannot be trusted. The presence and order of variable inclusion in this array is defined according to the PHP variables_order configuration directive. This array has no direct analogue in versions of PHP prior to 4.1.0. See also import_request_variables().
Caution
Since PHP 4.3.0, FILE information from $_FILES does not exist in $_REQUEST.
Note: When running on the command line , this will not include the argv and argc entries; these are present in the $_SERVER array.
$_SESSION: Variables which are currently registered to a script's session. Analogous to the old $HTTP_SESSION_VARS array (which is still available, but deprecated).

Php $_GET Variable

2005-05-03T12:37:00.001+05:30

php $_GET variable is a predefined php variable name, and values are sent by the HTTP GET method. Get method is not so profound, and the amount of data can be sent is max 100 characters, it displays data (including passwords and usernames) in user's browser address bar, Also makes it vulnerable to SQL injections (Kind of My SQL exploitation done by typing characters in address bar) .

However it is useful, when you want to point to a particular page to retrive data...

<a href="http://www.somesite.com/get_some_data.php?name=sandy>sandy's data</a>

Or collect Data from HTML form

<form name="someform" method="GET" action="toSomePhpFile.php">

Example :

"myform.html":

<form action="collect.php" method="GET">
Name: <input type="text" name="name" />
Email: <input type="text" name="email" />
<input type="submit" />
</form>

"collect.php"

<? php
echo $_GET["name"] .<br />";
echo $_GET["email"] . "years old! ";
?>

When user clicks submit button, it will look like this in address bar on the browser.

http://www.somesite.com/welcome.php?name=sandy&email=sandy@yahoo.com

Php $_POST Variable

2005-05-02T13:06:00.001+05:30

PGP $_POST variable is a predefined php variable name, and values are sent by the HTTP POST method, exactly like $_GET variable, but data sent from a form with $_POST method is invisible to user.

Example :

"myform.html":

<form action="collect.php" method="POST">
Name: <input type="text" name="name" />
Email: <input type="text" name="email" />
<input type="submit" />
</form>

"collect.php"

<? php
echo $_POST["name"] ."<br />";
echo $_POST["email"] ;
?>

With POST method you can send any amount of data from the HTML form. It is useful when you want to collect... large text, passwords etc.

What is Php

2005-04-15T09:40:00.001+05:30

Php is a server-side HTML embedded scripting language, for creating dynamic websites, it is free and provides full suite of tools to developers for building dynamic websites.

Php stands for PHP: Hypertext preprocessor and it's Open Source Software (OOS)
Php scripts are executed on the server, Which means users can not see code source from their browser.
Php supports many powerful databases such as MySQL, Oracle, Sybase, Solid etc.
Php is server-side scription language, simile to ASP.
The main thing about Php is that, it is free to download and use.
PHP runs on diffrent platforms (Windows, Linux, Unix, etc) and it's compatible with almost all servers used today.

Before you should learn Php, you must know few basic knowledge about HTML.

Install Php on Windows

2005-04-14T10:02:00.005+05:30

I have been using WampServer for a while, and it's an excellent piece of program, it comes bundled with MySQL, PHP 5, phpMyAdmin and Apache server. I strongly recommend that you use it. If still you want to go lengthy way, go on reading.

How to Install PHP on Windows IIS.
Please remmember PHP will not work on 16 bit platforms such as Windows 3.1. There are many ways you can install php in your windows. You can refer to This site that shows you nicely how to install Php, MySQL and Apache Server. Or you can follow PHP online guide to installation, which covers everything.

First Go to Php Download page and download a Windows Binaries package. You can choose php package with installer for automated installation or Zipped package for manual installation.
I've choosen to download PHP 4.4.6 zip package , You can choose newer ones, i.e php 5.x, which are now more reliable and has less bugs...

Windows NT/200x/XP and IIS 4 or newer
Where to find IIS? Well that's a common question. Go to Control panel > Administrative Tools > Internet Information Services. If you can not find it, that means you haven't installed it. To Install it, Put Windows CD, which is distributed with your computer, else you can ask your vendor for that. go to Control Panel > Add/Remove Programs > Add/Remove Windows Components > Check "Internet Information Services (IIS)", Which is approximately 15 MB in Size. Click details if you want to install additional services else click Next to start Installation.

Now extract Zipped Php Binaries package to a folder, usually C:\PHP , Avoid folders that contain long names, spaces or bad file names, such as "C:\my Php #$files here" . and do not mess with PHP file structure.

Go to Control panel > Administrative Tools > Internet Information Services.
Click to open IIS manager, Right click on "Default Web site" > Properties.
Under 'Home Directory', 'Virtual Directory', or 'Directory', do the following:
Change the Execute Permissions to 'Scripts only'
Click on the 'Configuration' button, and choose the Application Mappings tab.
Click Add and set the Executable path to the appropriate CGI file.
An example PHP 4 value is: C:\php\php.exe Supply .php as the extension.
Leave 'Method exclusions' blank, and check the 'Script engine' checkbox. Now, click OK a few times.

Set up the appropriate security. (This is done in Internet Service Manager), and if your NT Server uses NTFS file system, add execute rights for I_USR_ to the directory that contains php.exe / php-cgi.exe.

Click Play button on the toolbard to start Internet Information Services.

First PHP Script

2005-04-13T11:40:00.001+05:30

Hello World php

This is the most common thing you do when you learning PHP. first and foremost you need to know that php blocks starts with . Similar to Html Hello Which makes Text bold like this Hello. Php blocks can be placed anywhere in your Web documents, aslong as your your php file is .php extension.

Let's create our first php file. Open test editor such as Notepad.. or any other web editor programs such as dreamweaver. but avoid using MS word for god sake... duh!
Now write the following document.

By the way.. codes above are in gif image format! Just because i don't want you to copy and paste codes in your text editor, you need to type everything yourself.

Save this file as "hello.php" and upload or place it in your testing folder or your web sever.
To execute this script, type something like this in your browser address bar :

http://www.yoursite.com/testfolder/hello.php
or if it's in your local site :
http://localhost/testfolder/hello.php

Adding comments on the Code

Adding comments on your php code is a good habit, this way you'll always keep track of bugs & errors that continue to show up all the time in developers browser.

Go on test it.. you'll not see those comment lines or blocks on the code.
This comment lines are commonly used by all php developers, because it reduces the complexity of the code. Imagine 1000 lines of php code without comments on it.. it would be difficult task for developers to locate the bugs.. with comments on it, it is easy to figure out, what went wrong.

Well that's it, we will talk about if and else statements on next chapter.

PHP Operators

2005-04-12T13:06:00.001+05:30

PHP Operators
Below listed in the tables are the php operators, it is important that you memorize at least few of them.

Arithmetic Operators

Operator	Description	Example	Result
+	Addition	x=2 x+2	4
-	Subtraction	x=2 5-x	3
*	Multiplication	x=4 x*5	20
/	Division	15/5 5/2	3 2.5
%	Modulus (division remainder)	5%2 10%8 10%2	1 2 0
++	Increment	x=5 x++	x=6
--	Decrement	x=5 x--	x=4

Assignment Operators

Operator	Example	Is The Same As
=	x=y	x=y
+=	x+=y	x=x+y
-=	x-=y	x=x-y
*=	x*=y	x=x*y
/=	x/=y	x=x/y
%=	x%=y	x=x%y

Comparison Operators

Operator	Description	Example
==	is equal to	5==8 returns false
!=	is not equal	5!=8 returns true
>	is greater than	5>8 returns false
<	is less than	5<8>
>=	is greater than or equal to	5>=8 returns false
<=	is less than or equal to	5<=8 returns true

Logical Operators

Operator	Description	Example
&&	and	x=6 y=3 (x <> 1) returns true
\|\|	or	x=6 y=3 (x==5 \|\| y==5) returns false
!	not	x=6 y=3 !(x==y) returns true

Php IF & ELSE

2005-04-11T14:20:00.000+05:30

Php IF & ELSE Statemments

Php if, else statements in PHP can perform different actions, based on different conditions.
That means, sometimes you may want to show "bye, have a nice day" instead of "hello how are you?" in user's browser.

syntax :

if (condition)
Code.....
else
Code.....

Example :

$val = 1;
If ($val == 1)
echo "value is one";
else
echo "value is not one";

PHP IF & ELSEIF Statements.
Php elseif Statements is same as elseif statements. But this time you can extend the limit of your conditions.

Syntax :

if (condition)
code ...
elseif (condition)
code ...
elseif (condition)
code...
else
Code :

If ($val = 1)

echo "value is one";
elseif ($val == 2)
echo "value is two";
elseif ($val == 3)
echo "value is three";
else
echo "value is unknown";

Output of above code is :

value is three