Questions in: Core PHP

The implode() function takes an already existing array as
it's argument, and concatenates the contents of
each element in the array into a string.
where as explode() function performs reverse to implode()
function. It splits the string into items by a
delimiter, such as a dash, ampersand, space and places each
item into a new array.

explode function:-it breaks a string into array.
<?php
$str="hello world.it's a beautiful day.":
print_r(explode(" ",$str):
?>
ans-ARRAY
[0]=>hello
[1]=>world.
[2]=>it's
[3]=>a
[4]=>beautiful
[5]=>day.
implode:-returns a string from elements of an array.
<?php
$arr=array('hello','world!',beautiful,'day!');
echo implode(" ",$arr);
?>
ans-hello world! beautiful day!

post_max_size also should be greater than upload_max_filesize

default session time 1440.
we can change it by
$garbaze="14400";
ini_set(session_gc_maxlifetime,$garbaze);

default session time in PHP is 1440 seconds. if we want to
change the session time in php, then we have to change in
php.ini.

Use Following Code :
<?php
$objCom = new COM(“AddNumber.math”);
$result = $objCom ->AddTwoNum(2,2);
echo $result;
?>

<?php
dl(extension.dll); //as com
?>

Use
1. print()
2. echo()
3. printf() functions to give the output to a browser.

With the use of echo() and print() function we can give
output to a browser.

we are using get, post ,session, cookie method for passing
data. in get method it pass data through url. and post
passes data through hidden variable. and in session we
create session variable these variable store on server .
and cokkie same as session but cookie store at client
machine.

we are using get, post ,session, cookie, request method for
passing
data. in get method it pass data through url. and post
passes data through hidden variable. and in session we
create session variable these variable store on client
machine and Only SESSION ID stores on server.
and cokkie same as session but cookie store at client
machine.
Request method is same as get method. we use request method
for sending variables using href in <a> tag, or in
Javascript using document.location.href .

This is the Script:
<?php
if (isset($_POST["submit"]))
{
$textBox = $_POST["textBox"];
$dropdown = $_POST["dropdown"];
$check = $_POST["check"];
echo "Form submitted.";
}
else
{
echo "Please submit form";
}
?>
<form name="frm" method="post" action="<?php
$_SERVER["PHP_SELF"]?>" >
<input type="text" name="textBox" value="<?php echo
$textBox ?>" /><br />
<input type="checkbox" name="check" value="1" <?php if
($check == "1") echo "checked" ?> /><br />
<select name="dropdown">
<option <?php if ($dropdown == "Pankaj") echo "selected";
?> >Pankaj</option>
<option <?php if ($dropdown == "Bisane") echo "selected";
?> >Bisane</option>
<option <?php if ($dropdown == "MCS") echo "selected"; ?>
>MCS</option>
</select><br /><br />
<input type="submit" name="submit" value= "Submit" /><br />
</from>

A .mim or .mme file is a file in the Multipurpose Internet
Mail Extension (MIME) format.
MIME is a specification for the format of non-text e-mail
attachments that allows the attachment to be sent over the
Internet. MIME allows your mail client or Web browser to
send and receive things like spreadsheets and audio, video
and graphics files via Internet mail.
MIME was defined in 1992 by the Internet Engineering Task
Force (IETF). The distinguishing characteristic of a MIME
message is the presence of the MIME headers. As long as your
mail recipients also have e-mail software that is MIME-
compliant (and most e-mail software is), you can swap files
containing attachments automatically.
Here are some tips for e-mail attachments:
You can use a utility like WinZip (PC) or StuffIt (Mac) to
compress a large file before you send. Most e-mail systems
will not accept messages that exceed a certain size.
It is a good idea to send attached photographs in the Joint
Photographic Experts Group (JPEG) format rather than the GIF
or TIFF formats. JPEG (.jpg) files use less space and
therefore upload faster.
AOL and some e-mail software uses .mme or .mim files as a
"wrapper" for mail that contains non-text attachments. Use
care when sending a MIME attachment to users of older
versions of AOL software, as the earlier versions do not
handle MIME very well. Send one attachment per e-mail. If
you are an AOL user, use the keyword (Ctrl+K) MIME to view
help about decoding MIME files.

While using MIME email with PHP is a pretty fun process, the
bad news is that it can be quite challenging to implement,
particularly if you're not very familiar with its most
complex facets. There's also the possibility that you often
find yourself writing the same annoying code over and over
again, especially when you have to construct MIME email
modules within your applications.

$date1 = date('Y-m-d');
$date2 = "2007-07-05";
$days = (strtotime($date1) - strtotime($date2)) / (60 * 60
* 24);
echo " No of $days difference";

Something we must know about strtotime
(try putting up a date grater than 30 years)
yes it will give an unexpected output, because it uses, unix
timestamp, and thus doesnt treat a date greater than 30 yrs,
as a correct value.
Amazing but true

PHP supports Multi-level inheritence.It wont support
multiple inheritence,but we can achieve multiple
inheritence through interfaces.

PHP can support single,multilevel inheritance. And you can
use interfaces to achive multiple inheritace but not
directly multiple inheritance is allowed due to its
limitations

md5 means Messagedigest5 is an algorithem
converst the plain text to hipher text
mainly used in store the user passwords in database

With the md5 function you can encrypt your text with 32
character hexadecimal string.
For Ex.
$str = 'apple';
echo md5($str);
this prints '1f3870be274f6c49b3e31a0c6728957f'