1)What is PHP?
PHP: Hypertext Preprocessor
is open source server-side scripting language that is widely used for web
development. PHP scripts are executed on the server. PHP allows writing
dynamically generated web pages efficiently and quickly. The syntax is mostly
borrowed from C, Java and perl. PHP is free to download and use.
2)What is PEAR
in php?
PEAR(PHP Extension and
Application Repository) is a framework and repository for reusable PHP
components. PEAR is a code repository containing all kinds of php code snippets
and libraries.
PEAR also offers a
command-line interface that can be used to automatically install
"packages".
3)Explain how
to submit form without a submit button.
We can achieve the above
task by using JavaScript code linked to an event trigger of any form field and
call the document.form.submit() function in JavaScript code.
4)Echo vs.
print statement.
echo() and print() are
language constructs in PHP, both are used to output strings. The speed of both
statements is almost the same
echo() can take multiple
expressions whereas print cannot take multiple expressions.
Print return true or false
based on success or failure whereas echo doesn't return true or false.
5)$message vs.
$$message in PHP.
$message is a variable with
a fixed name. $$message is a variable whose name is stored in $message.
If $message contains
"var", $$message is the same as $var.
6)Explain the
different types of errors in PHP.
Notices, Warnings and Fatal
errors are the types of errors in PHP
Notices:
Notices represents
non-critical errors, i.e. accessing a variable that has not yet been defined.
By default, such errors are not displayed to the user at all but whenever
required, you can change this default behavior.
Warnings:
Warnings are more serious
errors but they do not result in script termination. i.e calling include() a
file which does not exist. By default, these errors are displayed to the user.
Fatal errors:
Fatal errors are critical
errors i.e. calling a non-existent function or class. These errors cause the
immediate termination of the script.
7)Explain the
importance of the function htmlentities.
The htmlentities() function
converts characters to HTML entities.
8)What is
MIME?
MIME - Multi-purpose
Internet Mail Extensions.
MIME types represents a
standard way of classifying file types over Internet.
Web servers and browsers
have a list of MIME types, which facilitates files transfer of the same type in
the same way, irrespective of operating system they are working in.
A MIME type has two parts: a
type and a subtype. They are separated by a slash (/).
MIME type for Microsoft Word
files is application and the subtype is msword, i.e. application/msword.
9)How to use
HTTP Headers inside PHP? Write the statement through which it can be added?
HTTP headers can be used in
PHP by redirection which is written as:
<?header('Location: http://www.php.net')?>
The headers can be added to
HTTP response in PHP using the header(). The response headers are sent before
any actual response being sent. The HTTP headers have to be sent before taking
the output of any data. The statement above gets included at the top of the
script.
10)Why PHP is
also called as Scripting language?
PHP is basically a general
purpose language, which is used to write scripts. Scripts are normal computer
files that consist of instructions written in PHP language. It tells the
computer to execute the file and print the output on the screen. PHP is used
for webpages and to create websites, thus included as scripting language.
11)What are
the steps involved to run PHP?
The steps which are involved
and required to run PHP is as follows:
1. Set up the web
environment.
2. Set up the web servers.
There are many web servers that are available and the mostly used is Apaches
which automatically remains installed with linux distribution and on windows it
is easy to install. There are other servers like IIS (Internet information
server) provided by Microsoft can be used to set up the web environment.
3. Install the web server
and PHP
4. Update and administer the
system for changes.
12)How can we
increase the execution time of a php script?
By the use of void
set_time_limit(int seconds)
Set the number of seconds a
script is allowed to run. If this is reached, the script returns a fatal error.
The default limit is 30 seconds or, if it exists, the max_execution_time value
defined in the php.ini. If seconds is set to zero, no time limit is imposed.
When called,
set_time_limit() restarts the timeout counter from zero. In other words, if the
timeout is the default 30 seconds, and 25 seconds into script execution a call
such as set_time_limit(20) is made, the script will run for a total of 45
seconds before timing out.
13)What are
the differences between Get and post methods in form submitting.give the case
where we can use get and we can use post methods?
The HTML 2.0 specification
says, in section Form
Submission (and the HTML 4.0
specification repeats this with minor
stylistic changes):
–>If the processing of a
form is idempotent
(i.e. it has no lasting
observable effect on the state of the
world), then the form method
should be GET. Many database searches
have no visible side-effects
and make ideal applications of query
forms.
––>If the service
associated with the processing of a form has side
effects (for example,
modification of a database or subscription to
a service), the method
should be POST.
14)How the
form data is transmitted?
quotation from the HTML 4.0
specification
–> If the method is “get”
– -, the user agent
takes the value of action,
appends a ? to it, then appends the form
data set, encoded using the
application/x-www-form-urlencoded
content type. The user agent
then traverses the link to this URI. In
this scenario, form data are
restricted to ASCII codes.
–> If the method is
“post” –, the user agent conducts an HTTP post
transaction using the value
of the action attribute and a message
created according to the
content type specified by the enctype
attribute.
15)Who is the
father of PHP and explain the changes in PHP versions?
Rasmus Lerdorf is known as
the father of PHP.PHP/FI 2.0 is an early and no longer supported version of
PHP. PHP 3
is the successor to PHP/FI
2.0 and is a lot nicer. PHP 4 is the current
generation of PHP, which
uses the
Zend engine
under the
hood. PHP 5 uses
Zend engine 2 which,
among other things, offers
many additionalOOP features
16)How can we
submit a form without a submit button?
The main idea behind this is
to use Java script submit() function in
order to submit the form
without explicitly clicking any submit button.
You can attach the
document.formname.submit() method to onclick,
onchange events of different
inputs and perform the form submission. you
can even built a timer
function where you can automatically submit the
form after xx seconds once
the loading is done (can be seen in online
test sites).
17)In how many
ways we can retrieve the data in the result set of
MySQL using
PHP?
You can do it by 4 Ways1.
mysql_fetch_row.
2. mysql_fetch_array
3. mysql_fetch_object
4. mysql_fetch_assoc
18)What is the
difference between mysql_fetch_object and
mysql_fetch_array?
mysql_fetch_object() is
similar tomysql_fetch_array(), with one difference -
an object is returned,
instead of an array. Indirectly, that means that
you can only access the data
by the field names, and not by their
offsets (numbers are illegal
property names).
19)What is the
difference between $message and $$message?
It is a classic example of
PHP’s variable variables. take the
following example.$message =
“Mizan”;$$message = “is a moderator of PHPXperts.”;$message is a simple PHP
variable that we are used to. But the
$$message is not a very
familiar face. It creates a variable name $mizan
with the value “is a
moderator of PHPXperts.” assigned. break it like
this${$message} =>
$mizanSometimes it is convenient to be able to have variable variable
names. That is, a variable
name which can be set and used dynamically.
20)How can we
extract string ‘abc.com ‘ from a string ‘http://info@abc.com’
using regular
expression of PHP?
preg_match(“/^http:\/\/.+@(.+)$/”,’http://info@abc.com’,$found);
echo $found[1];
21)How can we
create a database using PHP and MySQL?
We can create MySQL database
with the use of
mysql_create_db(“Database
Name”)
22)What are
the different tables present in MySQL, which type of
table is
generated when we are creating a table in the following syntax:
create table
employee (eno int(2),ename varchar(10)) ?
Total 5 types of tables we
can create
1. MyISAM
2. Heap
3. Merge
4. INNO DB
5. ISAM
MyISAM is the default
storage engine as of MySQL 3.23 and as a result if
we do not specify the table
name explicitly it will be assigned to the
default engine.
23)Suppose
your Zend engine supports the mode <? ?> Then how can u
configure your
PHP Zend engine to support <?PHP ?> mode ?
In php.ini file:
set
short_open_tag=on
to make PHP support
24)What is
meant by nl2br()?
Inserts HTML line breaks
(<BR />) before all newlines in a string
string nl2br (string);
Returns string with ” inserted before all
newlines. For example: echo
nl2br(“god bless\n you”) will output “god
bless <br /> you” to
your browser.
25)How can we
encrypt and decrypt a data present in a MySQL table
using MySQL?
AES_ENCRYPT () and
AES_DECRYPT ()