Question 1

How can we find the number of rows in a result set using PHP?

Accepted Answer

$result = mysql_query($sql, $db_link); $num_rows = mysql_num_rows($result); echo "$num_rows rows found";

Question 2

What is the functionality of md5 function in PHP?

Accepted Answer

Calculate the md5 hash of a string The hash is a 32-character hexadecimal number I use it to generate keys which I use to identify users etc If I add random no techniques to it the md5 generated now will be totally different for the same string I am using

Question 3

What are the differences between GET and POST methods in form submitting?

Accepted Answer

On the server side, the main difference between GET and POST is where the submitted is stored The $_GET array stores data submitted by the GET method The $_POST array stores data submitted by the POST method On the browser side, the difference is that data submitted by the GET method will be displayed in the browser’s address field Data submitted by the POST method will not be displayed anywhere on the browser GET method is mostly used for submitting a small amount and less sensitive data POST method is mostly used for submitting a large amount or sensitive data

Question 4

What is a Session?

Accepted Answer

A session is a logical object created by the PHP engine to allow you to preserve data across subsequent HTTP requests Sessions are commonly used to store temporary data to allow multiple PHP pages to offer a complete functional transaction for the same visitor

Question 5

Explain include(), include_once, require() and require_once.

Accepted Answer

include() The include() function takes all the content in a specified file and includes it in the current file If an error occurs, the include() function generates a warning, but the script will continue execution include_once() File will not be included more than once If we want to include a file once only and further calling of the file will be ignored then we have to use the PHP function include_once() require() The require() function is identical to include(), except that it handles errors differently The require() generates a fatal error, and the script will stop require_once() The required file is called only once when a page is open and further calling of the file will be ignored

Question 6

How can we extract string "abc.com" from a string "https://info@abc.com" using regular _expression of php?

Accepted Answer

We can use the preg_match() function with “/*@(*)$/” as the regular expression pattern For example: preg_match("/*@(*)$/","https://info@abccom",$data); echo $data[1]; ?>

Question 7

What are the different types of errors in php?

Accepted Answer

Notices: These are trivial, non-critical errors that PHP encounters while executing a script - for example, accessing a variable that has not yet been defined By default, such errors are not displayed to the user at all - although, as you will see, you can change this default behaviour Warnings: These are more serious errors - for example, attempting to include() a file which does not exist By default, these errors are displayed to the user, but they do not result in script termination Fatal errors: These are critical errors - for example, instantiating an object of a non-existent class, or calling a non-existent function These errors cause the immediate termination of the script, and PHP’s default behaviour is to display them to the user when they take place

Question 8

What is the functionality of the function strstr and stristr?

Accepted Answer

strstr() returns part of a given string from the first occurrence of a given substring to the end of the string For example: strstr("user@examplecom","@") will return "@examplecom" stristr() is idential to strstr() except that it is case insensitive

Question 9

What are the differences between mysql_fetch_array(), mysql_fetch_object(), mysql_fetch_row()?

Accepted Answer

mysql_fetch_array: Fetch a result row as an associative array and a numeric array mysql_fetch_object: Returns an object with properties that correspond to the fetched row and moves the internal data pointer ahead Returns an object with properties that correspond to the fetched row, or FALSE if there are no more rows mysql_fetch_row(): Fetches one row of data from the result associated with the specified result identifier The row is returned as an array Each result column is stored in an array offset, starting at offset 0

Question 10

What are encryption functions in PHP?

Accepted Answer

CRYPT(), MD5()

Question 11

How to set cookies?

Accepted Answer

setcookie('variable','value','time'); variable - name of the cookie variable value - value of the cookie variable time - expiry time Example: Test - cookie variable name $i - value of the variable 'Test' time()+3600 - denotes that the cookie will expire after an one hour

Question 12

How to store the uploaded file to the final location?

Accepted Answer

move_uploaded_file( string filename, string destination)

Question 13

Explain $_FILES Superglobal Array.

Accepted Answer

Array Descriptions -------------------------------- ----------------------------------- $_FILES['userfile']['name'] The original name of the file on the client machine $_FILES['userfile']['type'] The MIME type of the file if the browser provided this information An example would be "image/gif" $_FILES['userfile']['size'] The size, in bytes, of the uploaded file $_FILES['userfile']['tmp_name'] The temporary filename of the file in which the uploaded file was stored on the server $_FILES['userfile']['error'] The error code associated with this file upload

Question 14

What is Constructors and Destructors?

Accepted Answer

CONSTRUCTOR : PHP allows developers to declare constructor methods for classes Classes which have a constructor method call this method on each newly-created object, so it is suitable for any initialization that the object may need before it is used DESTRUCTORS : PHP 5 introduces a destructor concept similar to that of other object-oriented languages, such as C++ The destructor method will be called as soon as all references to a particular object are removed or when the object is explicitly destroyed or in any order in shutdown sequence

Question 15

What is PHP's configuration file called?

Accepted Answer

PHP’s configuration file is called phpini

Question 16

What is a PHP Filter?

Accepted Answer

A PHP filter is used to validate and filter data coming from insecure sources To test, validate and filter user input or custom data is an important part of any web application The PHP filter extension is designed to make data filtering easier and quicker

Question 17

What is Apache configuration file typically called?

Accepted Answer

The Apache configuration file is called httpdconf

Question 18

Which function would you use to insert a record into a database?

Accepted Answer

The dba_insert() function adds a record to a database

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